prominent part is played by the green mold (usually some strain of _P.
Roqueforti_) which grows throughout the cavities of its mass[77]. At
its best, it has attractive texture and flavor. Much of it fails to
reach high quality on account of the invasion of bacteria, _Oidium
lactis_, and very frequently myriads of cheese mites. The following
analysis was furnished as typical for ripe cheese by Miles Benson,[78]
late professor of dairying at Reading, England: Water 31 per cent, fat
36 per cent, casein 29 per cent, mineral constituents including salt
about 4 per cent. Approximately the same figures are given by Primrose
McConnell (Agricultural Note Book). The low percentage of salt is
another factor of uncertainty in the control of this Stilton product, as
in Gorgonzola, since these cheeses are commonly high in water-content at
first and are thus subject to invasion by Oidium.
Stilton has been made on a small scale in Canada[79] and occasionally
attempted in the United States. No serious effort to develop an industry
of commercial importance has been made in America. Comparative study of
the cheeses ripened by green mold tends to the conviction that the
adaptation of the Roquefort practice to the use of cow's milk offers a
more satisfactory basis for experiment than efforts to establish a
Stilton or a Gorgonzola industry.
+173. Gex.+--A cheese under this name made in southern France resembles,
in its general character as a ripened cheese, the English Stilton and
Italian Gorgonzola. Although it has no commercial importance, reference
is made to this cheese to show that mold-ripened cheeses have been
developed entirely independently in different countries to bring about
the same general character of product.
+174. Bacterially ripened series.+--The semi-hard cheeses ripened by
bacteria stand half-way between true Limburger and the hard forms. In
fact, brands of Limburger are readily found which approach the texture
and ripening of Brick cheese. In the same way, Brick cheeses are often
found which have the appearance, texture and much of the flavor of the
Cheddars with only a trace of the taste of Limburger. Port du Salut,
Oka, Münster, in France Livarot, in the Balkan regions Kascoval, belong
in this series.
+175. Brick cheese.+--The name of this cheese is probably due to the
finished product being about the size and shape of a brick. It is
similar to the German cheese Bäckstein and may have been developed from
it. It is typically a sweet-curd cheese, made from milk freshly drawn,
without permitting the development of appreciable quantities of acidity
until after the curd has been put into the hoop. In the making process,
it is intermediate between Limburger and the cheeses of the Cheddar
group. Some cheese-makers use an ordinary cheese vat, others a copper
kettle in manufacturing.
It is the usual practice to deliver the milk to the cheese factory both
morning and evening, without cooling. Cheese is made twice a day. In
some cases the milk is delivered only once a day, and extra precautions
must then be taken to care for the milk properly.
The discussion of the care of milk in Chapter II applies to that for
Brick cheese. For the best quality of cheese, the milk in the vat
should show about 0.15 of 1 per cent acidity and never above 0.18 of 1
per cent.[80]
+176. Making of Brick cheese.+[81]--The milk is received at the cheese
factory at a temperature of about 92° to 96° F. For the best results,
the acidity should be determined (by the acid test) to decide on the
amount of starter to use. Few Brick cheese-makers use an acid test or a
starter but these precautions would improve the product of many
factories. For method of using the acid test, see Chapter V. Chapter IV
discusses the preparation and use of starter. Usually 0.25 to 0.50 of 1
per cent of starter is the amount required. A small amount of starter is
used to aid the development of lactic acid and for the beneficial effect
it has on the flavor. A very small development of acid is desired after
adding the starter; therefore the change in acidity should be very
carefully watched with the acid test. The vat is usually set when the
acid test shows 0.16 of 1 per cent acidity. The more acid in the milk,
the less starter should be employed. Sufficient rennet extract should be
used to give a coagulation suitable for cutting in thirty to thirty-five
minutes. For method of adding the rennet extract, see Chapter V. When
the coagulum is firm enough for the curd to break clean over the finger,
it is ready to cut. The curd is cut with coarse knives into 3/8- or
½-inch cubes. After cutting, the curd is let stand three to five
minutes, then stirred with the hands for a few minutes until the whey
begins to separate and then stirred with the rake. Some makers do not
stir by hand but use the rake directly after cutting. When this is done,
great care must be exercised to stir the curd without breaking up the
pieces, because this causes a loss of fat. After cutting the curd is
stirred for twenty to thirty minutes before the steam is turned on. The
curd is heated very slowly at first and more rapidly during the last
stages of cooking. The curd is cooked to a temperature of 110° to 115°
F. The lower the temperature that can be used to produce firm curd, the
better the texture of the cheese. After cutting and during the cooking,
the curd must be constantly stirred so that lumps will not form. When
the curd forms lumps, the moisture is not evenly expelled. This results
in uneven texture and curing. Sometimes some salt is added to the curd
in the vat to restrain souring. The curd is stirred after cooking until
it is sufficiently firm. It remains usually in the whey for a total
period of one and one-fourth to one and one-half hours from the time of
cutting. It is then dipped into forms 10 inches long by 5 inches wide by
8 inches deep. The forms are without top or bottom and are placed on a
draining table. This table is so constructed that the whey can be saved
for stock feed. When ready to "dip," the whey is drawn down to the
surface of the curd in the vat, then the curd is dipped into the forms
or hoops. Care must be taken to get the same amount of curd into each
form to produce the cheeses of uniform size. Each cheese is turned
several times to insure even draining and even reduction of the
temperature. While draining, a follower is placed in each hoop and a
weight placed on each cheese. Usually a brick is used for this weight. A
cheese is allowed to drain or press for ten to fifteen hours. It is
then placed on the salting table and rubbed with coarse salt. While on
the salting table, a cheese is placed on its broad side. Some
cheese-makers prefer to salt their cheeses by soaking them in a salt
brine. This brine should be strong enough to float an egg. Salting
requires three days. The cheeses are then brushed free from excess salt
and taken to the cellar to cure or ripen.
+177. Ripening Brick cheese.+--For this process, the cellars are kept at
about 90 percent relative humidity and a temperature of 60° to 65° F.
Some prefer a temperature for curing as high as 68° F. During the
curing, the surfaces of the cheese are kept moist and mold growths kept
down by rubbing or brushing the cheese with pure water or salt and
water. In the curing cellars the cheeses are placed on shelves; at first
they are set close together and as they cure, they are separated. During
curing, the color changes from a whitish to a reddish brown. The cheese
cures from the outside toward the center. When first made, the product
is harsh and hard in texture but during the ripening process it becomes
mellow and smooth. The cheeses remain on the curing shelves for four to
six weeks, after which they are wrapped in heavy waxed paper and boxed.
A cheese ready for market usually weighs about five pounds. A Brick
cheese box is 5 inches deep by 20 inches wide by 3 feet long, and holds
110 to 115 pounds of cheese.
+178. Qualities of Brick cheese.+--The cheeses should be neat and
attractive and the rind not cracked or broken. The sides should be
square and not bulged. The cheese should have a clean, characteristic
Brick cheese flavor. The body and texture should be mellow and smooth
and when rubbed between the thumb and forefinger, should break down
like cold butter. The color should be uniform. The cheese should contain
the proper amount of salt and moisture. One of the worst faults with
Brick cheese is bad flavor. This is many times due to the cheese-maker
not using clean flavored starter. It may also be due to bad flavored
milk. A Brick cheese-maker has no means of controlling gassy
fermentations. These show themselves in the bad flavor of the cheese and
in the porous body. They also cause the cheese to bulge. If detected,
gassy milk should be rejected. If too much acid is developed, a sour
cheese is the result. This will not cure normally and usually has a sour
flavor. The body will be brittle and mealy. If too much salt is used,
the cheese may have a salty taste and it will cure very slowly. If not
enough salt is used, the cheese may cure too rapidly and undesirable
flavors and fermentations develop. The cheese must have the proper
moisture-content; if too much moisture is present, the cheese cures too
fast and is soft and pasty in body; if not enough moisture, then the
reverse is true. Tabulation of cheeses of special quality, as submitted
in scoring contests, show an average water-content of 37 to 38 per cent,
with occasional cheeses verging toward Limburger in texture and flavor
with 40 to 42 per cent water, and others indistinguishable from Cheddar,
with water-content as low as 34 per cent.
The Wisconsin Cheese-makers Association uses the following score-card
for the judging of Brick cheese on a scale of 100:
Flavor 40
Texture 40
Color 10
Salt 5
Style 5
---
100
+179. Composition and yield.+--The composition of Brick cheese varies
within wide limits. The average cheese probably contains from 37 to 39
per cent of water, although many cheeses are above and below this
average; Doane and Lawson[82] give the fat as 28.86 per cent, proteins
23.8 per cent and total ash 4.20 per cent.
The composition and yield are both affected by: (1) the moisture-content
of the cheese; (2) composition of the milk from which made; and (3)
losses during the manufacturing process. The average yield of Brick
cheese is 11 to 13 pounds to 100 pounds of milk.
+180. Port du Salut cheese.+--The Trappist monks originated this type of
cheese in their monasteries in France. Under the name of their community
Oka, it has been made and sold widely by the Trappist Fathers of Quebec.
In recent years, factories independent of the order have made such
cheese both in America and in Europe.
The following outline of the making process indicates the close
relationship between Port du Salut and Brick cheeses. Whole milk or milk
not over one-fifth skimmed is ripened to medium acidity, then heated to
90° to 95° F. according to season and acidity. Rennet enough is added
(see Chapter V) to curdle in thirty to forty minutes, although some
makers shorten the time to twenty minutes. When formed, the curd is cut
into small cubes and excess of whey is dipped away. The constantly
stirred mass is then heated or cooked to 100° to 105° F. within a period
of ten to twelve minutes or according to some makers twenty to thirty
minutes. It is allowed to stand a few minutes to settle. Most of the
whey is then drawn and the mass is stirred vigorously to prevent fusion
of the curd granules. The curd is ready for the hoop when the particles
are about the size of grains of wheat and do not stick together when
squeezed with the hand. The individual grains of curd should crumble
easily between the fingers. The hot curd is transferred directly to the
hoops without cooling. For this purpose, a hoop is set upon the table
covered with a cloth and the curd dipped into the cloth. The edges of
the cloth are then folded over. In this condition the cheese is
transferred to the press where gradually increasing pressure begins with
3 to 4 pounds and reaches about 70 pounds. To insure proper shape,
cheeses are turned and put into fresh cloths at the end of the first
hour and turned subsequently several times during the pressing period of
about twelve hours.[83]
Port du Salut cheeses are salted by rubbing fine salt on the surface by
hand at the rate of 1.2 to 2 per cent of the weight of the cheese. After
about two days in the salting process, they are put into the ripening
cellars. The cellars are wet, since they reach 90 to 95 per cent
relative humidity at a temperature of about 55° F. After two days in the
cellar, the cheeses are plunged into a tank of saturated brine to which
a trace of cheese color has been added. As they come out of these tanks,
they are yellowish and greasy or slimy. They are returned to the
shelves where they are rubbed every day with a cloth or by hands wet in
brine. After about one week they are again plunged in the brine.
Treatment with brine tends to insure a firm rind. The cheeses are rubbed
more or less regularly with brine through the whole ripening period.
After six weeks, such cheese may be eaten. The cut surface of Port du
Salut is creamy in color, may or may not show small holes. In texture it
is soft enough to spread readily under pressure without losing its shape
in handling. In flavor the cheese is a mild form belonging to the
Limburger group.
Port du Salut cheeses as imported from France usually are firm round
cakes about 1½ inches thick, weighing about 3 pounds.
CHAPTER XI
_THE HARD CHEESES_
The hard cheeses form a great series of groups, whose most prominent
physical character is their firm or hard texture. This is correlated
with comparatively low water-content, which is usually between 30 and 40
per cent. Although certain varieties occasionally test above 40 per cent
water, this deviation is accompanied by quick ripening and rapid
spoilage. These varieties of cheese are staple products with long
marketable periods; therefore they may be handled in large lots,
shipped, carted and stored freely without the losses such treatment
would entail in soft cheese. The retailer frequently buys hard cheese by
the ton, not by the cheese or by the box.
In making, these varieties are characterized as cooked and pressed
cheeses. Although both the heating of a curd and the pressing of a newly
made cheese occur among semi-hard forms, these practices appear in their
most typical forms in the hard cheeses.
The hard cheeses show two types of texture. A cut cheese may appear
smooth, free from holes or with a few angular cracks or seams, or it may
show round holes or "eyes." In the smooth textured forms every effort is
made to prevent gassy fermentations, usually by controlling the
fermentation of the curd in the making process. When "eyes" are present,
the end sought has been a development of a particular form of gassy
fermentation which gives this appearance and brings about the
characteristic ripening texture and flavor.
The hard cheeses have been developed in groups of national varieties.
The best known of these groups are those which may be represented by
English Cheddar, American Factory Cheddar, Danish, the Edam of Holland,
Swiss and Parmesan with many related varieties in Italy and neighboring
countries of southern Europe.
+181. The Danish group.+--The Danish cheeses are related in appearance
and flavor to the English group represented by Cheddar. The demand for
butter in Europe has been so great that the Danish cheese-makers have
developed skim and part skim varieties largely to the exclusion of the
whole milk form. Skillful handling of their process has resulted in a
product which has had a very large and appreciative market in England
and Germany.
+182. The Dutch group.+--Edam and Gouda are the two forms of cheese made
in Holland and most widely known among other peoples. Both reach America
in considerable quantities; both are shipped in large amounts to
tropical countries. Although attempts have been made to manufacture them
in America, no commercial production of these cheeses has been
successful. Although whole milk grades of these cheeses are known, they
are to a large measure part skim in manufacture. The presence of one or
both of these forms in every large market in America makes the general
facts of their production of general interest. Parts of a report on
experimental work in the making of Edam and Gouda are, therefore, given
here.
+183. Edam cheese+[84] is a sweet-curd type, made from partially
skimmed-milk. It comes to the market in the form of round red balls,
each weighing from 3½ to 4 pounds when cured. It is largely
manufactured in northern Holland and derives its name from a town famous
as a market for this kind of cheese.[85] Milk from which one-fourth to
one-third of the fat has been removed is used. Too great pains cannot be
taken in regard to the condition of the milk. It should be fresh, free
from every trace of taint; in brief, it should be in as perfect
condition as possible.
+184. Method of manufacture.+--The following paragraphs give the steps
in the manufacture of Edam cheese:
_Treatment of milk before adding rennet._--The temperature of the milk
should be brought up to a point not below 85° F. nor much above 88° F.
When the desired temperature has become constant, the coloring matter
should be added. Cheese color is used at the rate of 1½ to 2 ounces
for 1000 pounds of milk. The coloring matter should, of course, be added
to the milk and thoroughly incorporated by stirring before the rennet is
added.
_Addition of rennet to milk._--The rennet should not be added until the
milk has reached the desired temperature (85° to 88° F.) and this
temperature has become constant.
When the temperature reaches the desired point and remains there
stationary, the rennet extract is added. Rennet extract may be used,
4½ to 5½ ounces being taken for 1000 pounds of milk, or enough to
coagulate the milk in the desired time, at the actual temperature used.
The milk should be completely coagulated, ready for cutting, in about
twelve to eighteen minutes from the time the rennet is added. The same
precaution observed in making Cheddar cheese should be followed in
making Edam cheese with reference to care in adding the rennet, such as
careful, accurate measurement, dilution with pure water before addition
to milk.
_Cutting the curd for Edam._--When the curd breaks clean across the
finger, it should be cut; it is cut a very little softer than in the
Cheddar process as ordinarily practiced. As stated, this stage of
hardness in the curd which fits it for cutting should come in twelve to
eighteen minutes after the rennet is added. First, a vertical knife is
used and the curd is cut lengthwise, after which it is allowed to stand
until the slices of curd begin to show the separation of whey. Then the
vertical knife is used in cutting crosswise, after which the horizontal
knife is at once used. Any curd adhering to the bottom and sides of the
vat is carefully removed by the hand, after which the curd-knife is
again passed through the mass of curd lengthwise and crosswise,
continuing the cutting until the curd has been cut as uniformly as
possible into very small pieces.
_Treatment of Edam curd after cutting._--When the cutting is completed,
one commences at once to heat the curd up to the temperature of 93° to
96° F. The heating is done as quickly as possible. While the heating is
in progress, the curd is kept constantly agitated to prevent settling
and consequent overheating. As soon as the curd shows signs of
hardening, which the experience of the worker will enable him to
determine, the whey is drawn off until the upper surface of the curd
appears, when one should commence to fill the press molds.
[Illustration: FIG. 27.--Edam cheese mold.]
_Filling molds, pressing and dressing Edam._--The molds, which are
described later in detail, are well soaked in warm water previous to
use, in order to prevent too sudden chilling of curd and consequent
checking of separation of whey. As soon as whey is drawn off, as
indicated above, one begins to fill the pressing molds (Fig. 27). The
filling should be done as rapidly as possible to prevent too great
cooling of curd. When the curd has been put into the molds, its
temperature should not be below 88° F. Unless care is taken to keep the
curd covered, the portion that is last put into the molds may become too
much cooled. In making Edam cheese on a small scale, it is a good plan
to squeeze the moisture out with the hands as much as possible and then
break it up again before putting in the molds, when the curd should be
pressed into the mold firmly by the hands. The molds should be filled as
nearly alike as possible. The cheese should weigh from 5 to 5¼ pounds
each when ready for the press. When the filling of molds is completed,
they are put under continual pressure of 20 to 25 pounds for about
twenty-five or thirty minutes. While the cheese is being pressed, some
sweet whey is heated to a temperature of 125° or 130° F., and this whey
should not be allowed to go below 120° F. at any time while it is being
used. When the cheeses are taken from their molds, each is put into the
warm whey for two minutes, then removed and dressed. For dressing Edam
cheese, the ordinary cheese bandage cloth is used. This is cut into
strips, which should be long enough to reach entirely around the cheese
and overlap an inch or so, and which should be wide enough to cover all
but a small portion of the ends of the cheese when put in place. Before
putting on the bandage, all rough projections should be carefully pared
from the cheese. In putting on, the cheese is held in one hand and the
bandage is wrapped carefully around the cheese, so that the whole is
covered, except a small portion on the upper and lower surface of the
cheese. These bare spots are covered by small pieces of bandage cloth of
a size sufficient to fill the bare surface. The bandage is kept wet with
the warm sweet whey, thus facilitating the process of dressing. After
each cheese is dressed, it should be replaced in the dressing mold, care
being taken that the bandage remains in place and leaves no portion of
the surface of the cheese uncovered and in direct contact with the mold.
The cheese is then put under continual pressure of 60 to 120 pounds and
kept for six to twelve hours.
+185. Salting and curing Edam.+--There are two methods which may be
employed in salting,--dry and wet. In dry-salting, when the cheese is
finally taken from the press, it is removed from the press mold, its
bandage is removed completely, and the cheese placed in another mold,
quite similar, known as the salting mold. Each cheese is placed in a
salting mold with a coating of fine salt completely surrounding it. The
cheese is salted in this way once each day for five or six days. Each
day the cheese should be turned when it is replaced in the mold, so that
it will not be rounded on one end more than the other.
In the method of wet-salting, the cheese is placed in a tank of salt
brine, made by dissolving common salt in water in the proportion of
about 1 pound of salt to 2½ quarts of water. Each cheese is turned
once a day and should be left in the brine seven or eight days. When
the cheese is taken from the salting mold or salt bath, it is placed in
warm water and given a vigorous, thorough brushing in order to remove
all slimy or greasy substances that may have accumulated on the outer
surface. When the surface is well cleansed, the cheese is carefully
wiped dry with a linen towel and placed upon a shelf in the curing-room.
In being put on the shelves, the cheeses should be placed in contact so
as to support one another, until they have flattened out at both ends so
much that they can stand upright alone. Then they are moved far enough
apart to allow a little air space between them. Another method of
securing the flattened ends is to support each cheese on opposite sides
by wedge-shaped pieces of wood. After being placed on the shelves in the
curing-room, they are turned once a day and rubbed with the bare hand
during the first month, twice a week during the second month and once a
week after that. When any slimy substance appears on the surface of the
cheese, it should be washed off at once with warm water or sweet whey.
The special conditions of the curing-room will be noticed in detail
below. When the cheeses are about two months old, they can be prepared
for market in the following manner: They are first made smooth on the
surface by being turned in a lathe or in some other manner, after which
the surface is colored. For coloring, some carmine is dissolved in
alcohol or ammonia to secure the proper shade, and in this color-bath
the cheeses are placed for about one minute, when they are removed and
allowed to drain, and as soon as they are dry the outside of each cheese
is rubbed with boiled linseed oil, in order to prevent checking. They
are then wrapped in tin-foil, which is done very much like the
bandaging. Care must be taken to put on the tin-foil so that it presents
a smooth, neat appearance. The cheeses are finally packed in boxes,
containing twelve cheeses in each box, arranged in two layers of six
each with a separate partition for each cheese.
+186. Equipment for making Edam cheese.+--Careful attention must be
given to the moisture and temperature of the curing-room. This room
should be well ventilated, quite moist and its temperature kept between
50° and 65° F. These are conditions not easy to secure in any ordinary
room. Some form of cellar is best adapted for these conditions. The
amount of moisture can be determined by an instrument known as a
hygrometer. In a curing-room suited for Edam cheese, the moisture should
be between 85 and 95 per cent, or a little short of saturation. When the
temperature is between 50° and 65° F., the moisture is between 85 and 95
per cent if the wet-bulb thermometer is from 1 to 2° F. (or ½ to 1°
C.) below the dry-bulb thermometer. Cheese will check or crack and be
spoiled for market, if the degree of moisture is not kept high enough.
Aside from the molds, press and salting vat, the same apparatus that is
used in making Cheddar can be used for Edam cheese. The pressing mold is
turned preferably from white wood or, in any case, from wood that will
not taint. Each mold consists of two parts; the lower constitutes the
main part of the mold, the upper portion is simply a cover. The lower
portion or body of the mold has several holes in the bottom, from which
the whey flows when the cheese is pressed. Care must be taken to prevent
these holes being stopped up by curd. This part of the mold is about six
inches deep and six inches in diameter across the top. The salting mold
has no cover and the bottom is provided with only one hole for the
out-flow of whey; in other respects it is much like the pressing mold.
+187. Qualities and yield of Edam cheese.+--The flavor of a perfect Edam
cheese is difficult to describe. It is mild, clean, and pleasantly
saline. In imperfect Edams, the flavor is more or less sour and
offensive. In body, a perfect Edam cheese is solid, rather dry and mealy
or crumbly. In texture, it should be close and free from pores. In the
experiments here reported the amount of fat in 100 pounds of the
partially skimmed-milk varied from 2.45 to 3.20 pounds and averaged 2.77
pounds. Of this amount, from 0.30 to 0.51 pound of fat was lost in the
whey, with an average of 0.39 pound. The yield of cheese from 100 pounds
of milk varied from 9.60 to 11.82 pounds and averaged 10.56 pounds.
+188. Gouda cheese.+[86]--This Dutch variety is a sweet-curd cheese made
from whole milk. In shape, the Gouda cheese is somewhat like a Cheddar
with the sharp edges rounded off and sloping toward the outer
circumference at the middle from the end faces. They usually weigh 10 or
12 pounds, though they vary in weight from 8 to 16 pounds. They are
largely manufactured in southern Holland, and derive their name from the
town in which they were first made. Fresh sweet milk that has been
produced and cared for in the best possible manner should be used.
+189. Method of manufacture.+--The processes of manufacturing Gouda
cheese are as follows:
_Treatment of milk before adding rennet._--The temperature of the milk
should be brought up to a point not below 88° F. nor much above 90° F.
When the desired temperature has been reached and has become constant,
the coloring matter is added. One ounce of cheese color for about 1200
pounds of milk may be used. The coloring matter should be thoroughly
incorporated by stirring before the rennet is added.
_Addition of rennet to milk._--The rennet should not be added until the
milk has reached the desired temperature (88 to 90° F.) and this
temperature has become constant. The milk should be completely
coagulated, ready for cutting, in fifteen or twenty minutes. The same
precautions should be used in adding rennet as those previously
mentioned in connection with the manufacture of Edam cheese.
_Cutting the curd._--The curd should be cut when it is of about the
hardness generally observed for cutting in the Cheddar process. The
cutting is done as in the Cheddar process except that the curd is cut a
little finer in the Gouda cheese. Curd should be about the size of peas
or wheat kernels when ready for press and as uniform in size as
possible.
_Treatment of curd after cutting._--After the cutting is completed,
heating and stirring is begun at once. The heating and constant stirring
is continued until the curd reaches a temperature of 104° F., which
should require from thirty to forty minutes. When the curd becomes
rubber-like in feeling, the whey should be run off. The whey should be
entirely sweet when it is removed.
_Pressing and dressing Gouda._--After the whey is off, the curd is put
in molds at once without salting (Fig. 28). Pains should be taken in
this process to keep the temperature of the curd as near 100° F. as
possible. Each cheese is placed under continuous pressure amounting to
ten or twenty times its own weight and kept for about half an hour. The
first bandage is put on in very much the same manner as in Edam cheese
making. The cheese is then put in press again for about one hour. The
first bandage is then taken off and a second one like the first put on
with great care, taking pains to make the bandage smooth, capping the
ends as before. The cheese is then put in press again and left twelve
hours or more.
[Illustration: FIG. 28.--Gouda cheese mold.]
_Salting and curing._--When Gouda cheese is taken from the press, the
bandage is removed and it is placed for twenty-four hours in a
curing-room like that used for Edam cheese, as previously described.
Each cheese is then rubbed all over with dry salt until the salt begins
to dissolve, and this same treatment is continued twice a day for ten
days. At the end of that time, each cheese is carefully and thoroughly
washed in warm water and dried with a clean linen towel. The cheeses are
then placed on the shelves of the curing-room, turned once a day and
rubbed. The temperature and moisture are controlled as described in the
curing process of Edam cheese. If the outer surfaces of the cheese
become slimy at any time, they are carefully washed in warm water and
dried with clean towels. Under these conditions, cheese ripens in two or
three months.
+190. Equipment for Gouda cheese.+--The molds, press and curing-room
are the only equipment needed in the making of Gouda cheese that differ
from that employed in making Cheddar cheese. The mold used for Gouda
cheese consists of two portions, which are shown separately in Fig. 28.
These molds are made of heavy pressed tin. The inside diameter at the
middle is about 10 inches, that of the ends about 6½ inches. The
height of the mold is about 5½ inches, and this represents the
thickness of the cheese, but by pushing the upper down into the lower
portion, the thickness can be decreased as desired.
+191. Composition and yield of Gouda.+--In work with milk averaging 4.2
per cent of fat there were lost in the whey from 0.29 to 0.43 per cent
with an average of 0.35 per cent of fat. The loss of fat appears to be
not much greater than the average loss met with in cheese factories in
making Cheddar cheese. From 100 pounds of milk, there were made from
11.60 to 13.35 pounds of green cheese, with an average of 12.50 pounds.
The percentage of water in the experimental cheese varied from 41.25 to
45.43 per cent and averaged 43.50 per cent.
CHAPTER XII
_CHEDDAR CHEESE-MAKING_
Cheddar is the best known cheese throughout the United States and the
one most commonly made in factories. The Cheddar process was brought to
America by English immigrants. Similar to Cheddar cheese are Pineapple,
English Dairy, Sage cheese, skimmed-milk and California Jack cheese made
in this country, and Derbyshire, Leicestershire, Wensleydale and
Cheshire made in England. The Cheddar cheese process as employed in the
factories to-day has been modified and improved since it was first
introduced into this country by the early immigrants. The following
description[87] includes only the practices as found in the factories
to-day if whole milk is used. Skimmed-milk Cheddar cheese is discussed
later.
+192. The lot-card.+--The Cheddar process involves several hours of
manipulation and includes many details which should be closely and
accurately observed and recorded. The necessity of carrying observations
of several different factors at the same time makes a scheme of
recording data essential to convenient work. For this purpose, a
lot-card for Cheddar cheese is introduced here and the pages given to
particular factors are indicated in the space intended for the recording
of observations. The manufacture of Cheddar cheese is a complicated
process, because several factors must be given attention at the same
time. A careful record of the observations of each step in the
successive handling of each lot of milk puts the operator in possession
of a permanent record of his experience. This record has several uses.
It may help to convince patrons of the importance of eliminating faults
in the milk; it furnishes the cheese-maker a cumulative record of his
experiences in handling milk with special qualities, such as high or low
fat-content, over-acidity or taints. Since Cheddar ripening covers a
period of weeks and months, no operator can remember particular lots of
milk sufficiently well to be able to use his experience on the
interpretation of the qualities found in the ripened product.
[Illustration: FIG. 29.--Delivering milk to the cheese factory.]
+193. The milk.+--It is the usual practice to deliver the milk to the
cheese factory each morning (Fig. 29). The night's milk is cooled and
kept clean and cold until delivered at the factory. It is advisable not
to mix the cold night's milk and the warm morning's milk, but to deliver
them in separate cans to the cheese factory at the same time. The milk
is weighed, sample for fat test taken and then run into the vat (Fig.
30). The receiving or taking in of the milk is one of the most important
parts of the cheese factory work. It is practically as important as the
actual manufacturing of the cheese.
+21 CHEESE.+ This card must remain with lot ........... from the milk room
until the finished product is ready to leave the building, then it should
be handed to instructor.
+MAKING+ Day and Date ................................ Vat ...............
+Milk | |
Used+ | | +Milk+
........................|............| Appearance of Milk ................
........................|............| Odor ..............................
........................|............| Taste .............................
Total pounds |............| Weather conditions ................
------------------------+------------+------------------------------------
...........% fat ...........lbs. fat | +Starter+
| Kind used..........................
....% solids not fat ....lbs. s.n.f. | Flavor.............................
| Acidity............................
....% casein ....lbs. casein. | Amount used.......... % used.......
-------------------------------------+------------------------------------
+Time of Minutes+ | +% Acid+ | +Temperature+
adding starter }...... | _In Milk_ | of milk when received
} | | when starter added...
adding rennet }...... | when received............| when rennet added....
} | before adding starter....| when whey removed....
coagulation }...... | after adding starter.....| at pressing..........
} | when rennet added........+----------------------
cutting }...... | | +Rennet Test+
} | | when milk received...
turn'g on steam }...... | _In Whey_ | after adding starter.
} | after curd is cut....... | when rennet added....
turn'g off steam}...... | at dipping.............. +----------------------
} | at packing.............. | +Hot Iron Test+
dipping }...... | at milling | at dipping...........
} | at milling | at packing...........
packing }...... | at salting | at salting...........
} +--------------------------+----------------------
milling }...... | +Condition of Curd+
} |
salting }...... | when cut........................................
} | when packed.....................................
hooping }...... | when milled.....................................
} | when salted.....................................
pressing }...... | when pressed....................................
} +-------------------------------------------------
dressing }...... | Amount per | +Color+ | +Rennet+ | +Salt+
| 1000 lbs. milk |.........|..........|........
Total time from }....| | | |
setting to pressing} | Total Amount |.........|..........|........
------------------------+-------+-----------+---------+----------+--------
% fat in lbs. fat estimated | If comments are added on
.......whey ....... so lost. | reverse side, put cross here............
% of total milk | Work and
....fat lost in whey | Observations by.........................
Assisted by...............................................................
--------------------------------------------------------------------------
+YIELD+ Day and Date......................... Time.......................
Serial
Weight of cheese when removed from press to curing room,......lbs. No....
lbs. milk for Kind of cheese made lbs. cheese per
..........one lb. cheese. ................... ......100 lbs. milk
lbs. cheese for one No. of cheese made. lbs. cheese for one
..........lb. fat in milk. ................... ....lb. total solid
If comments are added on reverse side put cross here...........
Work and observations by..................................................
--------------------------------------------------------------------------
Arranged by W. W. Hall.
[Illustration: FIG. 30.--Receiving, sampling, weighing and running the
milk into the cheese vat.]
Any milk high in acid or with a bad flavor should be avoided. It is
often bad policy to reject the milk, for a neighboring factory will
accept it and the factory not only loses the milk but also the patron.
Factories should have an agreement to prevent this. The acidity can be
determined by the acid test, but the detection of flavors must be made
by the cheese-maker himself with the aid of smell and taste. Many of
the bad flavors in the cheese can be traced to the poor quality of the
milk. One of the worst qualities in milk and cheese is the presence of
gas-producing organisms.[88] Any milk which shows gassy fermentation
should be rejected, for it is difficult to make cheese from this and at
best there will be a large loss during the manufacturing process. The
cheese may have a bad flavor and develop "pin-holes" and in extreme
cases may puff up like a ball. The person receiving the milk should talk
to the farmers or dairy-men about the proper care of the utensils and
milk. He must see that the cans are kept clean. One very bad practice is
to deliver milk and take home whey in the same cans. The cans, as they
are brought back from the cheese factory full of whey, are often left in
the barn or near a hog-pen until the whey is fed. Unless such cans are
emptied immediately on returning to the farm and then rinsed out with
cold water, thoroughly washed and scalded, bad flavors may develop in
the cheese. It is thought that this causes "fruity" or sweet flavor,
which resembles that of fruits such as raspberries, strawberries or
pineapples.
+194. Ripening the milk.+--A slight development of acidity is required:
(_a_) to obtain the formation of a firm curd; and (_b_) to establish
immediate dominance of a desirable type of lactic organism which will
produce the large amount of acid required later in the cheddaring
process. The development of this acidification before the addition of
rennet is known as the ripening of the milk. The extent of ripening
advised by different schools of makers has varied from an acidity of
0.20 of 1 per cent or even slightly higher percentage titrated as lactic
acid, to about 0.17 of 1 per cent as now preferred by some of the most
successful groups of workers. The ripeness of the milk can also be
determined by the use of the rennet test.
The milk may be ripened by allowing the lactic organisms already present
in the milk to develop naturally. This requires considerable time and
while the lactic acid-forming bacteria are developing, other and
undesirable fermentations may be taking place, so that the good results
which should follow the uninterrupted development of the lactic
acid-forming organisms are lost. Starter is commonly used to produce the
desired ripening of the milk. (For the preparation of starter see
Chapter IV.)
[Illustration: FIG. 31.--Steel cheese vat.]
Some makers put the starter into the empty vat (Fig. 31) and add the
milk as it is received; others add it to the total volume of cold milk
and then begin to heat it. Whenever the starter is used, it should be
strained to remove lumps. These lumps might cause a mottled color in the
cheese. The best practice calls for an acidity or a rennet test of the
mixed milk after it has been brought to the setting temperature in the
vat. With milk tested at this stage and the volume of milk in the vat
known, the cheese-maker is able to calculate closely the amount of
starter needed. When the quantity of starter to use is in doubt, the
amount added should be under rather than over the estimate, since the
need of more can be determined by making frequent rennet and acid tests
in a very few minutes without damage to the cheese. If too much starter
has been used, acid or sour cheese is usually obtained, with loss in
market quality.
An over-development of acidity at any stage of the manufacturing process
affects the flavor, body and texture, color and finish of the cheese.
The product is known as a sour cheese, and can usually be identified by
its sour taste and smell. A sour cheese while curing will seldom develop
a normal Cheddar flavor and the texture will be hard and harsh and very
brittle. The body will not be smooth but harsh and grainy. The
over-development of acid will show by fading or bleaching the color. A
sour cheese usually leaks whey for a few days after being placed on the
curing-room shelves.
Ripening the milk is one of the most important parts of cheese-making.
Proper ripening places the acid fermentations under the control of the
cheese-maker so that he may know what results will follow his labors.
The operator can control the acidity while ripening the milk, but after
the rennet is added all control of the acidity is lost. From that time,
the moisture must be regulated in proportion to the acidity.
Before setting, the milk should be ripened to such a point as to leave
at least two and one-half hours from the time that the rennet extract is
added until the acid development has reached the stage at which it is
necessary to remove the whey. By the acid test the milk may vary from
0.16 to 0.18 of 1 per cent, but no definite statement can be given for
the rennet test. This can be determined only by comparison from day to
day. For operation of rennet test see Chapter V. During this period of
two and one-half hours, the curd is formed, then cut, and the
temperature is raised from 84° or 86° F. (the temperature at which the
rennet extract is added) to about 98° to 100° F. The curd must be kept
agitated so that the particles will not mat together; this is necessary
to obtain sufficient contraction of the particles of curd with the
proper reduction of water-content. If the milk becomes too ripe (too
sour) before the rennet is added, there will not be sufficient time for
these steps to take place naturally. In such cases special means are
required to firm the curd. These result in a loss of both quality and
quantity of cheese. On the other hand, if the milk is not ripened, but
the rennet extract added, regardless of the acid development, one of the
important natural forces for expelling the moisture is lost. The time
required for the particles of curd to contract is much prolonged, the
expulsion of whey is usually inadequate and the curd remains in a soft
or wet condition. Using too much starter is almost equally bad, for
although it hastens the making process, it produces a sour or acid
cheese.
+195. Setting or coagulating.+--The milk for Cheddar cheese-making is
heated to 86° to 88° F. or occasionally a slightly lower temperature.
This temperature is found by experiment to give the texture of curd most
favorable for the desired results. Although some cheese-makers work as
low as 84° F., the texture of such curd is too soft and coagulates too
slowly. The very slight change of 2° F. produces curd which coagulates
more quickly and is tougher and firmer.
If the cheeses are to be colored, the color should be added after all
the starter. It should be thoroughly and evenly mixed with the milk to
insure an even color in the cheese. If the color is added before the
starter, there are likely to be white specks in the cheese, on account
of the coagulated casein in the starter. The amount of color to use
depends on the tint desired in the cheese. It varies from 1/3 to ½
ounce to 1000 pounds of milk for a light straw color to 1½ to 2
ounces for 1000 pounds of milk for a deep red color.
Enough rennet should be used to produce a curd firm enough to cut in
twenty-five to thirty-five minutes. The necessary amount will vary with
the strength of the rennet extract itself, with the acidity, the
temperature, the nature of the lot of milk, and with the individual aims
of the maker in which he adjusts the other factors to his preferences as
to rapidity of rennet action. With the usual commercial extract, the
needed amount ranges from 2.5 to 4 ounces for 1000 pounds of milk. As
for all varieties of cheese, the rennet extract should be diluted in
cold water at about one part rennet to forty parts water and thoroughly
stirred into the milk. (See Chapter V.)
+196. Cutting.+--The object of cutting is to obtain an even expulsion of
the moisture from the curd. The curd is cut as soon as it becomes firm
enough. To determine this, various tests may be used. Some operators
test it by pressing it away from the side of the vat, considering it
ready to cut when it separates cleanly from the metal. The test most
commonly used is to insert the index finger obliquely into the curd,
then to start to split the curd with the thumb and finally to raise the
finger gently; if ready to cut, the curd will split cleanly over the
finger and clear whey will separate to fill the opened crack. Another
arbitrary but more or less satisfactory rule is that the time from
adding the rennet until cutting should be two and one-half times that
from the addition of rennet until the first sign of coagulation is
observed.
The condition of the curd itself is the best guide to show when it is
ready to cut. The condition of the curd is constantly changing, so that
in a large vat, if the cutting is not begun until the curd is in the
best condition, by the time the last of the curd is cut it will be too
hard or firm. It is better to begin while the curd is a trifle too soft
so that the cutting will be taking place while the curd is at the proper
stage. At best the last of the curd may become too hard. If too hard, it
will break ahead of the knife instead of cut. Breaking causes more fat
loss than cutting because there is more surface exposed and hence more
fat globules. The softer the curd when cut, the quicker and easier the
moisture can be expelled.
If the curd is cut when soft, care must be exercised not to stir it too
hard immediately after cutting. Soft curd breaks very easily. When the
curd is cut soft and then stirred vigorously, there is a larger loss of
fat than when the curd becomes hard before it is cut.
Two knives are used to cut the curd. (See Fig. 11.) These knives may
have either wire or blades for cutting. The space between the wires or
blades varies from 5/16 to ½ inch. Knives used should have blades or
wires close enough together to cut the pieces as small as desired,
without a second cutting. When the curd has to be cut a second time it
usually results in pieces of uneven sizes, because the pieces already
cut cannot be evenly split in two.
One set of knives has horizontal and the other perpendicular blades or
wires. The curd is cut the long way of the vat with the horizontal knife
and lengthwise and crosswise with the perpendicular knife so that the
result is small cubes or oblongs of curd. Some cheese-makers prefer to
use one knife first and some the other, but the result should be a curd
cut into pieces of uniform size. The smaller the particles of curd or
cubes are cut, the quicker the curd will firm up or cook. If not cut
uniformly, the changes taking place later in the curd particles will not
be uniform,--the small pieces will be hard and dry while the large ones
will be soft and mushy.
[Illustration: FIG. 32.--The proper way to put the knife into the curd.]
Care should be taken to let the knife cut its way into the curd (Fig.
32). If the knife is pushed into the curd, it will break it and cause a
large loss of fat. The same is true when taking the knives out of the
curd. The loss of fat due to cutting is very similar to the loss of
sawdust when sawing a board. It may be considered a necessary evil. The
loss due to cutting is about 0.3 of 1 per cent of fat in the whey and
the loss of casein about 0.1 of 1 per cent in the whey.
[Illustration: FIG. 33.--Acme curd rake.]
[Illustration: FIG. 34.--McPherson curd agitator.]
+197. Heating or "cooking" the curd.+--After the curd is cut, the pieces
(cubes) rapidly settle to the bottom of the vat and tend to mat
together. To prevent this, the curd must be kept stirred. When stirring
first begins, the curd is soft and very readily broken. Some
cheese-makers prefer to stir by hand for the first few minutes after
cutting, while the curd is soft. The importance of careful handling can
hardly be over-emphasized. No matter how well the curd has been cut, if
the stirring is performed in a careless manner in the early stages, it
will be broken into uneven sized pieces and a considerable loss of fat
will result. A wooden hay rake or a McPherson curd agitator (Figs. 33,
34) may be used to stir the curd. Mechanical curd agitators are used in
some cheese factories. There are several makes. (See Fig. 35.) These
agitators save much hand labor, although some stirring by hand must be
done in connection with them. The mechanical agitators do not stir the
curd in the corners of the vat; this must be done with the hand rake. It
is the usual practice to stir the curd immediately after cutting for
five to ten minutes before the mechanical agitators are used. This is
necessary to give the curd a slight chance to firm as the mechanical
agitators tend to break it up. After cutting, a thin film forms on each
piece of curd. This film holds the curd particles, especially the fat.
Breaking the films on the cubes causes loss of fat. If lumps form at
the early stage, by matting of the curd particles, violent stirring is
required to separate them. When such lumps are broken up, new cleavage
lines are formed with loss of fat, because the original films
surrounding the soft curd fuse so firmly that the curd cubes do not
separate but actually break. New surfaces are thus formed with
consequent fat loss. Rapid shrinkage with expulsion of whey takes place
during the first few minutes of gentle agitation. Before any heat is
applied to the vat, sufficient whey should have separated or formed to
float each piece of curd separately. This will require ten to fifteen
minutes from the time of cutting.
[Illustration: FIG. 35.--Two types of mechanical curd agitators.]
Thus far the first of three distinct factors which expel the moisture
from the curd has been considered: (1) the action of the rennet; (2) the
development of the lactic acid; and (3) the application of heat. These
forces must have time to act naturally. If heat is applied too soon
after the curd is cut or if the temperature is raised too rapidly, it
causes a thick film to form on the pieces of curd which interferes with
the escape of the whey. The outside of the curd becomes firm but the
inside remains very soft. A curd which is cooked on the outside only
feels firm when stirred by hand in the whey, but when a handful is
squeezed the soft centers are noticed. To firm such curd masses requires
violent stirring, which will break the thick tough film. This allows the
moisture to escape and also increases the fat loss. The rapidity of
heating should depend on the condition of the curd and the amount of
acid developed. The heat should keep pace with these. When ready to
raise the temperature, the least amount of steam possible should be
allowed to pass through the valve. This should raise the temperature
very gradually. If heat is applied too quickly at first, it will cause
the curd to lump. A safe rule is to raise the temperature one degree in
the first five minutes after the steam has been turned on. The heating
should progress slowly until the whole mass of curd in the vat has
reached a temperature of 90° to 92° F. The usual temperature to which
the curd is heated or cooked is 98° F. to 100° F. The lower the
temperature that can be used and properly firm the curd, the better will
be the body of the cheese. If the curd is heated too high, it will
become hard, which causes a dry hard "corky" cheese. After this
temperature has been reached, there is not such a tendency for the curd
particles to stick together nor are they so easily broken in stirring.
It should require, under normal conditions, not less than thirty to
forty-five minutes, from the time the steam is turned on, to raise
temperature of the curd from the setting temperature to that necessary
to "firm" the curd. If a shorter time is allowed to raise the
temperature, the curd will not have opportunity to contract naturally.
The temperature required to expel the moisture properly varies with the
percentage of fat in the milk. If rich in fat (4.5 to 5.5 per cent) milk
requires a temperature of 98° to 104° F. to firm the curd, while the
same result can be accomplished with milk testing 3.0 to 3.5 per cent
fat at a temperature of 94° to 96° F. A higher temperature is needed in
winter than in summer because the milk is usually richer in fat. In a
water-jacketed vat, allowance must always be made for the rise in
temperature due to the water surrounding it. The water may be removed if
there is danger of the temperature going too high. However, it is better
to gauge the heat so that the water may be left, as this helps to hold
the curd at an even temperature, especially in cold weather. In a
steam-heated vat there is not so much danger of the temperature running
up.
The stirring must be kept up after the steam has been turned off until
the curd has reached such a stage of contraction that it will not
readily pack or mat in the bottom of the vat. After the curd reaches
this stage it may be allowed to settle to the bottom and stirred only
occasionally until it is time to remove the whey. If the cheese room is
not warm and there is danger of the curd cooling, a cover should be
placed on the vat. The curd should not be allowed to settle for more
than fifteen minutes without stirring to keep each piece separate. This
is necessary to obtain uniform contraction of all curd masses.
+198. Removing the whey.+--To permit the normal changes in the curd to
take place naturally, two and one-half hours from the time the rennet
extract is added is ordinarily required before the whey is drawn. The
time of removing the whey is determined by two factors: one, the acid
development, and the other, the firmness of the curd. For the best
results, it is better to have the firmness of the curd a trifle ahead of
the acid development. When the proper acid development has been reached,
the whey must be removed, regardless of the firmness of the curd. If the
curd has not become firm enough by natural forces, when the acid
development has reached the proper stage to remove the whey, it must be
firmed by other means. If it is not firm enough, either by natural or
artificial means, when the whey is removed, a sour cheese is the result.
The acid development should not be allowed to go beyond 0.16 to 0.19 of
1 per cent acidity in the whey by the acid test or 1/16 to 1/8 of an
inch of acid on the hot-iron test, before the whey is removed.
+199. Hot-iron test.+[89]--This test is employed to determine the amount
of acid in the curd. A piece of iron, such as an iron pipe two feet
long, is heated in the fire to proper temperature. If the iron is too
hot it will burn the curd, and if not hot enough the curd will not stick
to the iron. When hot, it is taken from the fire and wiped clean with a
cloth. A handful of curd is taken from the vat and squeezed dry, either
in the hand or in a cloth. This curd is carefully pressed against the
hot iron and drawn away. If the iron is at the right temperature and the
curd has sufficient acid development, the curd will stick to the iron
and when pulled away will form fine threads. The length of these threads
determines the amount of acid in the curd. The acid is usually spoken of
in terms of the length of threads, as 1/8 inch of acid, ½ inch of acid
and the like. The curd must have a slight development of acid before it
will stick to the iron. This test takes advantage of the peculiar
properties[90] of curd which are produced by the action of the acid on
the casein.
+200. Firmness of the curd.+--The cheese-maker must be able to judge the
firmness of the curd by physical examination. The particles of curd
should have shrunken to about one-half their original size and should be
of uniform consistency throughout; they should not have any soft
centers. The curd should be firm and springy. When a double handful is
pressed and suddenly released, the curd particles should spring apart.
The curd should have a "shotty" feeling when in the whey. If the curd
has attained the proper firmness, and the acid has not reached the
correct stage to remove the whey, it may be left in the whey until
sufficient acid development has been attained. This is liable to cause
the curd to become too firm and to result in a hard dry cheese. If there
is no evidence of the presence of undesirable organisms, such as bad
odors, or gas holes in the curd, it is better to remove the whey and
develop the acid when the curd is in the "pack." The pack refers to the
first piling of the curd.
[Illustration: FIG. 36.--Whey siphon with strainer.]
The whey may be removed either by means of a faucet or gate in the vat
or by a siphon (Fig. 36). With either form of removal a whey-strainer
(Fig. 37) should be used to prevent loss of curd particles. It requires
considerable time for the whey to escape from a large vat. After the
curd has been heated to the proper temperature, it is well to remove a
portion of the whey. In doing this the surface of the whey should not be
drawn down quite to the top of the curd. When ready, the remaining whey
can be quickly removed.
[Illustration: FIG. 37.--Whey strainer with spout to fit into the gate
in the vat.]
If it is decided that the curd is not firm enough, when the whey is
drawn down to the surface of the curd and the acid has developed
sufficiently, the curd should be firmed up in the whey by stirring it
vigorously by hand before the remainder of the whey is removed. This is
commonly called "hand stirring." This difficulty results either from the
use of too much starter or from holding the milk until too much acid
development has taken place before adding the rennet. Hand stirring
accomplishes what natural forces would accomplish if given sufficient
time. If the curd does not firm naturally in the whey, there is a large
loss of fat and other solids, because the pieces of curd will have to be
broken up to allow the water to escape from the soft centers of these
masses. This loss can usually be reduced by firming the curd in the whey
or adding water rather than by stirring without either water or whey. If
the curd is not properly firmed, it carries extra whey into the cheese.
With the increase in whey, the amount of milk-sugar carried into the
cheese increases. This extra milk-sugar attacked by bacteria produces an
excess of lactic acid, which results in "sour" cheeses. This explains
why the curd is placed beyond the danger of over-development of acid by
removing so large a portion of the whey. If the curd is properly firmed
in the whey and the whey is removed before too much acid has developed,
it is impossible to make a sour cheese.
+201. Gathering the curd together.+--Before the last of the whey has
been removed, the curd should be pushed back from the faucet into the
upper two-thirds of the vat and spread in an even layer. This layer
should be six to eight inches thick. The curd can be pushed back with
the rake or a board which will fit crosswise in the vat, in which are
many holes. As soon as the whey has been removed so that there is not
enough to wash the curd into the lower part of the vat, the vat should
be tilted and a ditch eight to ten inches wide cut in the curd through
the center. The curd from the ditch should be removed to either side and
spread evenly. As soon as all the whey has been removed, the pieces of
curd scattered about in the vat should be gathered up and placed with
the remainder.
In some factories, instead of matting the curd in the vat, a curd sink
is used. This is a wooden receptacle about the size of the vat but not
so deep, with a slatted false bottom. It is fitted with castors so that
it can be easily moved about. A cloth is placed in the sink and the curd
and whey are dipped upon the cloth. The whey escapes very rapidly
through the cloth. The curd sink is an advantage in those cases in which
it is desirable to remove the whey from the curd quickly, such as high
acid curds which have to be hand stirred to firm the curd. The
disadvantage lies in the work required to keep the sink and the large
cloth clean.
+202. Matting or cheddaring+ is the distinctive feature of the Cheddar
process. It is the piling and matting of the curd. Whether the curd is
matted in the vat or in the curd sink, the process is practically the
same. The object of cheddaring is three-fold: (1) to control the
incorporation of moisture; (2) to control undesirable ferments, if
present in the curd; (3) to develop the texture desired in the cheeses.
[Illustration: FIG. 38.--A cheese knife.]
After the curd in the vat has become matted so that the particles stick
together, the masses on either side of the central channel are cut
crosswise into strips with a cheese knife (Fig. 38). The width of the
strip depends on the water-content of the curd at this stage. The more
water, the smaller should be the pieces of curd. This allows the whey to
drain away much more rapidly. As soon as the strips of curd are cut,
they should be turned over or stood on edge. A drain should be left
along the middle line of the vat and on each side. This permits the whey
to run away freely. If, on the other hand, the outlet is dammed up, the
curd may become "whey-soaked." This produces a soft mushy cheese which
sometimes is "acidy" or sour. After the curd is turned each time, all
crumbs of curd broken off should be brushed underneath the masses of
curd so that they will mat with it. They should never be placed on top
of the curd because they will not unite but will become dry and hard. If
the crumbs are not kept brushed up, they become dry and will cause an
open textured granular cheese and possibly lumps in the cheese. After
the pieces of curd have been turned several times, and the whey has
fairly completely drained away, they may be piled first two deep, then
three deep and so on, the depth of the piling being gauged by the
softness or amount of water in the curd and the temperature. The higher
the curd is piled, the more water it will retain (assimilate), so that
the amount of moisture in the curd is regulated by the size of the
pieces into which it is cut and the rapidity and depth to which it is
piled.
The curd should not be left too long from the time it is turned until it
is turned again. This period is usually about ten to fifteen minutes.
The moister the curd, the more often it should be turned. In turning,
care should be taken to keep the ends at the same temperature as the
remainder. This can be done by piling them inside, thereby keeping them
warm. There is a tendency for the ends of the pieces of curd to remain
granular and so cause an open-textured cheese.
During the cheddaring process, the temperature should be reduced
uniformly and gradually. If there is danger of the curd becoming too
cold, the vat should be covered and a pail of hot water may be placed
inside, if it is deemed necessary. The temperature of the curd should
not be allowed to go below 85° to 90° F. If kept too warm, the curd will
become soft and plastic, and if too cold, it will not mat together.
While the curd is being turned and piled, its physical properties are
changing. The acid develops. When the cheddaring process is completed,
the curd should be elastic, smooth and fibrous. The curd should have the
close meaty texture desired in the cheese. If this step in the process
is neglected, defects may appear later in the body, texture and flavor
of the cheese. Attempts to pile the curd too fast result in a soft,
mushy, open-textured product. Such cheese has mechanical holes, in which
moisture collects, and so is likely to cause rot while curing.
If gas is detected either before or during the cheddaring process, the
curd should be piled until the gas holes are no longer round but flat.
If the gas holes are not flattened or obliterated during this process,
the cheeses will be very liable to puff on the shelves in the
curing-room. The curd should be handled until the gas holes flatten out
evenly, although this may require considerable time. At best, gassy curd
will never produce the highest grade of cheese.
Cheddaring or piling the curd is not thoroughly understood by most
cheese-makers. Because the moisture contains the milk-sugar, there is
danger of having so much moisture present in the cheese that it will
become sour from the action of the lactic acid-forming bacteria on the
milk-sugar. A cheese may be sweet when made and later become sour
because it contains too much moisture or milk-sugar. This is known as
"shelf souring." For the proper cheddaring of a curd, it is necessary
that it be properly firmed in the whey. If the moisture is not evenly
incorporated, the cheese will have a mottled color. The pieces that have
the more moisture will be lighter colored. If the proper amount of
moisture is not incorporated, the cheese will be dry and hard, and if
too much, soft and pasty.
+203. Milling the curd.+--The large pieces formed by the cheddaring
process must be cut into small ones before the curd can be easily put
into the hoop. This is called "milling." Properly milled curd can be
salted evenly, cools more quickly and uniformly and can be distributed
evenly in the hoops.
The proper time to "mill" the curd is determined by its physical
condition. Some curds will cheddar much more rapidly than others, hence
no definite length of time can be given. Curd, when ready to mill,
should have a fibrous texture somewhat like the white meat of a chicken
breast. The pieces of curd should split very easily. When cut, the curd
should show a close, solid, smooth interior. The amount of lactic acid
developed may vary within rather wide limits. The hot iron may show
strings ½ to 1 inch long. The acidity (by titration of the freshly
separating whey) may be 0.45 to 0.65 of 1 per cent. If the curd has been
properly made, that is, firmed up in the whey with the proper acidity so
far, acid development during the cheddaring process will take care of
itself. The physical condition remains the principal means of
determining the time when the curd should be milled.
[Illustration: FIG. 39.--Gosselin curd-mill.]
[Illustration: FIG. 40.--Barnard curd-mill.]
[Illustration: FIG. 41.--Junker curd-mill.]
[Illustration: FIG. 42.--Harris curd-mill.]
There are many kinds and styles of curd-mills on the market. Gosselin,
Barnard, Pohl, Junker, Victor, Harris are well-known kinds (Figs.
39-42). Some are hand, others power mills. Some of these tear the curd
into pieces of unequal size, others cut it into uniform pieces. A mill
that will do the work with the least possible pressure on the curd and
which will cut it into small uniform-sized pieces is most desirable. The
ideal mill should release the least fat and leave the curd in the best
condition to receive the salt. It is impossible to run curd through any
mill without exposing some fat on the freshly cut surfaces, and if the
curd is put under pressure, more fat will be pressed out and lost.
Cutting in the mill, like cutting the curd after coagulation by rennet,
may be called a necessary evil. There is an unavoidable mechanical loss
which may be greater or less according to the mill used. If the curd has
been properly handled so that the water in it has become thoroughly
assimilated (properly incorporated), this loss will be reduced to the
minimum. If the curd contains free moisture and many of the particles
have soft interiors, a stream of white whey will run down the vat as the
curd masses are cut. Some samples of such white whey will test as high
as 15 per cent fat. This not only causes a loss in yield but in quality
of cheese, according to the amount of fat lost. White whey is an
indication of loss of fat. If the proper amount of moisture is present
and is so thoroughly incorporated in the curd that it can be separated
only by evaporation, the ideal condition has been reached. While
milling, the cut curd should be stirred as fast as milled to prevent
matting again and to allow odors to escape. This stirring is usually
performed with a curd fork (Fig. 43). At the same time the temperature
will be lowered. The milled curd should be spread evenly over the upper
three-quarters of the bottom of the vat. The flavor of the curd that has
been made from tainted milk can be very much improved by stirring at
this time so that air can enter.
[Illustration: FIG. 43.--A curd fork.]
A gassy curd, which has been held until the holes have become flattened,
should be stirred very frequently during this stage to allow the gas to
escape, thereby improving the flavor.
+204. Salting.+--Salt is added to Cheddar curd for several purposes: (1)
for its taste; (2) to aid in the removal of the whey and to harden and
shrink the curd; (3) to influence the fermentation by slowing down
acidification, checking the growth of unfavorable organisms and delaying
ripening. The salt should be pure. It should be coarse-grained, because
the large grains dissolve more slowly and permit its absorption to a
much larger extent than the fine-grained salt. Salt that dissolves
slowly is, therefore, to be sought for this purpose.
The following factors must be considered in determining the amount of
salt to be used: (1) the amount of curd from the milk; (2) the
percentage of water in the curd; (3) the acidity of the curd; (4) the
particular market form of cheese desired. The custom of determining the
quantity of salt by the weight of milk is an inaccurate practice. The
amount of salt should be based on the amount of curd. If the amount of
fat in the milk is known, a fairly accurate estimate of the amount of
curd can be made. It would be more accurate to weigh the curd before
salting, but this is not practicable or necessary to insure a good
quality of cheese. The amount of salt varies from 1½ to 2½ pounds
of salt to the curd from each 1000 pounds of milk.
The salt should not be added directly after milling because, at that
time, it would cause a large loss of fat. After milling there should be
time before salting for the freshly cut surfaces to dry or "heal over."
When first milled the curd has a dry harsh feeling; when ready to salt
it will feel soft and mellow and some moisture can usually be squeezed
out easily. Fifteen to twenty minutes from the time of milling are
required before the curd is ready for the salt. When ready, the curd
should be spread evenly over the bottom of the vat. The salt should be
carefully weighed, and then applied, evenly, over the surface of the
curd, in two or three applications. The curd should be thoroughly
stirred after each application of salt. While the salt is being
dissolved and absorbed, the curd should be stirred occasionally to
prevent lumps from forming.
[Illustration: FIG. 44.--Wilson press hoop. _A_, complete hoop; _B_,
bottom cover with wide flange; _C_, top cover with narrow flange; _D_,
closed body; _E_, bandager.]
[Illustration: FIG. 45.--Fraser press hoop. _A_, complete hoop; _B_,
bandager; _C_, follower; _D_, fibrous press ring.]
+205. Hooping the curd.+--When the salt has become dissolved and the
curd as soft and mellow as before the salt was added, it is ready to be
put into the hoop. Various sized hoops may be used, depending on the
desired size of the cheese. Two types are the Wilson and the Fraser
(Figs. 44, 45). With either type, a dampened press cloth should be cut
just to fit the bottom of the hoop. A starched circle may or may not be
used; if used, it should be placed on top of the press cloth. The
bandage now commonly employed is the seamless one which comes in the
form of a tube of various sizes for different sized hoops. The lengths
of bandage cut for each hoop or cheese depend on the height of the
cheese plus about one and one-half inches' lap on each end. The bandage,
after being cut the desired length, is placed on the part of the hoop
made to hold it, so that it is suspended about the side of the hoop and
laps about one and one-half inches on the bottom. The bandage should be
free from ravelings and placed squarely in the hoop.
The hoop is now ready to fill with curd. Enough hoops should be prepared
to hold all the day's curd as fast as it is ready. In order to have all
the cheeses as nearly as possible of the same size, it is advisable to
weigh the curd into the hoops. The curd may be measured into the hoops,
but this is not so accurate. The curd may be dipped with a flat-sided
curd pail or a curd scoop into the hoops (Fig. 46).
[Illustration: FIG. 46.--Curd scoop and pail.]
+206. Pressing the curd.+--The natural changes sought in the curd
require a period of at least five hours between the time of setting
(addition of the rennet) and the pressing of the curd. Less time than
this involves loss in yield and quality of the cheese. In other words,
the time requirement for these changes cannot be ignored. The object of
pressing is not primarily to remove whey but to produce the physical
conditions essential to ripening the cheese in a mass and put it in
convenient form for handling. The whey should have been removed during
the cooking and cheddaring. When ready for the press, the temperature of
the curd should be about 80° to 85° F.; it should be brought down to
this point during the milling, salting and hooping processes. If the
curd is put to press too warm or too cold, the following results may be
expected:
Too high temperature during pressing produces several faults, as:
(1) Favors the development of undesirable ferments.
(2) Causes excessive loss of fat.
(3) Gives the curd pieces a greasy surface so that they
will not readily pass into a compact cheese. If a cheese
is greasy, the bandages will not stick.
(4) Favors the formation of mechanical holes in the
cheese.
(5) Causes "seamy" color in the cheese by the collection
of fat between pieces of curd.
Too low temperature has its difficulties, such as:
(1) The pieces of curd will not fuse together.
(2) The rind does not form properly.
(3) It appears to cause mottled cheese.
[Illustration: FIG. 47.--Continuous pressure gang cheese-press.]
[Illustration: FIG. 48.--Filling the hoops and pressing the curd.]
The commonly used gang press may or may not have an arrangement to cause
continuous pressure to be applied to the cheese (Figs. 47, 48). When
fresh cheeses are first placed in the press, the pressure should be
applied very gradually. The curd, after being cut through the mill, will
have many exposed fat globules. A heavy pressure at first will force
out the whey set free by the extracting power of the salt. The whey will
carry away the exposed fat globules, and therefore reduce the yield. As
soon as white whey starts from the hoops, the increased application of
the pressure should be stopped until the whey regains the appearance of
clear brine. More pressure can then be gradually applied until full
pressure is reached. The cheeses should remain under heavy pressure for
one-half to one hour, when they should be removed from the press and
dressed.
+207. Dressing the cheese.+--When ready to dress the cheese, the press
is opened and the hoops turned down. The hoops are opened so that the
bandages can be lapped over the top of the cheeses about 1½ inches.
Before turning a bandage down, it should be carefully pulled up to
remove any wrinkles from the sides of the cheese, but not hard enough to
pull it free from the bottom. After it is pulled up, the bandage should
be lapped over the top about 1½ inches, and if not even should be
trimmed with a sharp knife. It should then be sopped down with warm
water. Plenty of warm water to wet the bandage and cloths helps to form
a good rind. If starched circles are used, one should be placed on the
top of the cheese and sopped down with warm water. If not, the press
cloth should be wrung out of warm water and put on smoothly, so there
will be no wrinkles. The hoop is then put together and placed back in
the press under heavy pressure for twelve to eighteen hours. The
pressure should be sufficient to cause the curd particles to unite so
that the surface of the cheese will be smooth. The next day the cheeses
are taken from the hoops and placed in the curing-room. If they do not
come out of the hoop easily, they may be loosened by cutting between the
sides of the cheese and the hoop with a knife. A special thin-bladed
knife for this purpose is called a speed knife (Fig. 49). Care should be
taken not to cut the bandage when trying to loosen the cheese. If
starched circles are used, the press cloths are removed from the cheese,
when they are put in the curing-room. If neither starched circles nor
press cloth are left on the cheese in the curing-room, the rind will
crack on account of drying out on the exposed surface. This allows mold
and insects to enter the cheese. The flavor, body and texture and color
of the cheese are all dependent on the skill of the cheese-maker and the
quality of the milk from which it is made. The finish is dependent
entirely on the skill and carefulness of the maker. An operator should
see that the cheese press is straight so that there will be no crocked
cheese and that the bandage and press cloths are properly put on,
because the finish or appearance of the cheese is an index of his
ability.
[Illustration: FIG. 49.--Speed knife.]
+208. Handling over-ripe and gassy milk.+--Because it is sometimes
necessary to make over-ripe[91] or gassy milk[92] into cheese, special
directions or precautions are necessary. The best way is to reject this
milk. When it is necessary to make it into cheese, the losses are much
more than with normal milk. It is a question of making as good a cheese
as possible, and the subject of losses is ignored.
(1) _Over-ripe milk._--The fact that the milk is over-ripe shows that
there is already too much acid present. Every effort must be made to get
the curd as firm as possible in the whey with the acid development as
low as possible or before the acid has had time to develop any more than
can be helped. Although the milk is over-ripe, it is a good plan to add
about ¼ of 1 per cent of starter just before the rennet. This starter
will not begin to work until the curd is being cheddared and it will
help the flavor, especially if any bad fermentation should be present.
The rennet is added at 80° F., as this lower temperature tends to check
the acid development. More rennet is used, commonly from 4 to 4½
ounces to 1000 pounds of milk. This gives a quicker coagulation. The
curd is cut soft, as this tends to expel the moisture more quickly. The
heat is turned on sooner after cutting. The time to turn it on and the
length of time to heat are determined by the amount of acid. A curd
should not be heated in less than fifteen minutes. If the curd has
enough acid and has not begun to firm up much, the whey should be drawn
down to the surface of the curd, water the temperature of the whey and
curd put into the vat, and the curd firmed up in this water. The water
washes the acid out of the curd and because of the lack of milk-sugar
checks the acid development.
If the milk is not so ripe and the curd nearly firm enough, the whey may
be drawn off and the curd firmed up by hard stirring in the vat or sink.
The curd should not be pushed back enough to be very deep or thick when
ready to cheddar.
The curd should be cut into very small pieces to cheddar. The smaller
the pieces, the faster the whey drains away. Sometimes it is necessary
to cut the curd into pieces six inches square. The pieces should not be
piled but should be turned often and stood on edge to let the whey drain
away and sometimes pressed with the hands to force the whey out. It is
often all one man can do to keep the curd turned.
[Illustration: FIG. 50.--At the left is a regular shaped, close, solid
textured cheese; at the right one puffed up with gas.]
The curd is not cheddared very long but is milled early so that the whey
can escape. If it is thought that the cheese will be sour, the curd
should be washed in cold water to remove the acid and milk-sugar. A
little more salt is sometimes used. A product made from over-ripe milk,
no matter how skillful the cheese-maker, will show traces of a sour
cheese.
(2) _Gassy milk._--If a cheese-maker knows that there is "gassy"
fermentation, he should add more starter and develop more acid when
ripening the milk to try to overcome this. There are different kinds of
gassy fermentation. Some produce acid and some do not. Some will not
show until the cheeses have been on the curing-room shelves several
days. Others will cause the curd to float in the whey. Usually the gas
shows as pin-holes while the curd is being cheddared.
[Illustration: FIG. 51.--This shows the same cheeses as in Fig. 50, cut
open to show the solid and gassy texture.]
The gas causes tiny round holes in the cheese, resulting in the cheese
swelling or puffing out of shape and sometimes breaking open (Figs. 50,
51). The only time to overcome the gas is during the cheddaring process.
The curd is piled and repiled until the holes flatten out. This shows
that the gas-producing organisms have weakened and will not cause any
more holes. Because the curd has to be piled so many times and so long,
the pieces become very thin. The curd is ready to mill when most of the
holes have flattened. After milling, the curd should be stirred and
aired for some time before salting to allow the bad odor to escape.
Because of the high acid development, it often happens that the cheese
will not be gassy but will be sour. At best a cheese made from milk
having gassy fermentation will have a bad flavor. The quality of the
cheese can be no better than that of the milk from which it is made,
plus the skill of the cheese-maker.
+209. Qualities of Cheddar cheese.+--The cheese should be neat, clean
and attractive. If unclean, and the bandage not put on the cheese
properly, it shows that the manufacturer is not particular to keep the
curing-room shelves tidy nor careful and painstaking in dressing. The
cheese should not be lopsided or bulged. When cut, it should have a
uniformly colored interior. The principal color defects are too high, or
too light color, mottled or seamy. The texture should be solid and
close. A common defect is mechanical holes or openings and another is
gas pockets. The body can be tested by rubbing the cheese between the
thumb and fingers. It should be smooth and waxy and free from lumps. It
should rub down like cold butter. The common defects are graininess and
lumpiness. Graininess may be caused by too much acid or too much
moisture in the cheese. Lumpiness is due to uneven curing. If too much
moisture is present, the body will be soft and mushy; if not enough
moisture, the body will be hard and dry.
The cheese should have a pleasant, clean, mild aroma and the
characteristic flavor which is usually somewhat similar to that of nuts
and so is spoken of as a nutty flavor.
CHAPTER XIII
_COMPOSITION AND YIELD OF CHEDDAR CHEESE_
So many factors affect the composition and yield of Cheddar cheese that
no positive or exact statement can be made unless other facts are
definitely known. The following factors affect both the composition and
yield:
1. The chemical composition of the milk.
2. Amount of moisture incorporated into the cheese.
3. The amount of solids lost in cheese-making.
4. The skill of the cheese-maker.
5. The bacterial-content of the milk.
+210. Composition of milk, whey and cheese.+--The
following Tables[93] VI, VII, VIII, which are the average
of forty-eight factories for the season of 1893, show the
minimum, maximum and average composition:
TABLE VI
AVERAGE COMPOSITION OF THE MILK
| Minimum | MAXIMUM | AVERAGE
--------------------|---------|---------|---------
Water | 86.28 | 88.30 | 87.28
Total solids | 11.70 | 13.72 | 12.72
Fat | 3.30 | 4.40 | 3.77
Casein | 2.20 | 2.85 | 2.48
Albumin | 0.52 | 0.81 | 0.69
Sugar and ash, etc. | 5.63 | 5.89 | 5.78
TABLE VII
AVERAGE COMPOSITION OF THE WHEY
| Minimum | MAXIMUM | AVERAGE
--------------------|---------|---------|---------
Water | 92.75 | 93.28 | 93.00
Total solids | 6.72 | 7.25 | 7.00
Fat | 0.24 | 0.51 | 0.38
Casein, albumin | 0.66 | 0.99 | 0.86
Sugar, ash, etc. | 5.63 | 5.86 | 5.76
TABLE VIII
AVERAGE COMPOSITION OF THE GREEN CHEESE
| Minimum | MAXIMUM | AVERAGE
--------------------|---------|---------|---------
Water | 33.16 | 43.89 | 37.33
Total solids | 66.84 | 56.11 | 62.67
Fat | 30.00 | 35.89 | 33.41
Casein | 20.80 | 25.48 | 23.39
Sugar, ash, etc. | 4.86 | 7.02 | 5.89
Table VI shows the minimum, maximum and average composition of the milk
and Table VIII the composition of the cheese made from that milk. The
average composition of the cheese in Table VIII shows that it contains
37.33 per cent of water. The tendency to-day seems to be for a softer
cheese so that the average would probably be higher. Table VIII also
shows the wide variation in the composition of the cheese. The moisture
and total solids both vary about 10 per cent. In order to judge the
variation in composition, one must know the composition of the milk and
the moisture-content of the cheese and then only a very inaccurate
estimate of the composition of the cheese can be formed.
+211. Relation of fat to casein in normal milk.+--In order to understand
the relation of the composition of the milk to yield of cheese, one must
be familiar with the relation of the fat to the casein in normal milk.
The following table[94] shows the relation of fat to casein in normal
milk:
TABLE IX
SUMMARY SHOWING THE RELATION OF FAT TO CASEIN
IN NORMAL MILK
====================================================================
| | | | | AVERAGE
| | | AVERAGE | AVERAGE | POUNDS OF
| PER CENT | NUMBER | PER CENT | PER CENT | CASEIN FOR
GROUP | OF FAT IN | OF | OF FAT IN | OF CASEIN | EACH POUND
| MILK | SAMPLES | EACH IN | EACH | OF FAT IN
| | | GROUP | GROUP | MILK
--------+-----------+----------+-----------+-----------+------------
I | 3.0-3.5 | 22 | 3.35 | 2.20 | 0.66
II | 3.5-4.0 | 112 | 3.72 | 2.46 | 0.66
III | 4.0-4.5 | 78 | 4.15 | 2.70 | 0.65
IV | 4.5-5.0 | 16 | 4.74 | 3.05 | 0.64
V | 5.0-5.25 | 7 | 5.13 | 3.12 | 0.61
====================================================================
Table IX shows that the pounds of casein for each pound of fat are not
constant but that the casein does not increase in proportion to the fat
above 4.0 per cent of fat in the milk.
+212. Influence of fat in milk on yield of cheese.+--The following table
shows the influence which fat in the milk has on the yield of
cheese:[94]
TABLE X
SUMMARY SHOWING RELATION OF FAT IN MILK TO YIELD
OF CHEESE
==============================================================
| AVERAGE PER | POUNDS OF GREEN CHEESE | POUNDS OF
GROUP | CENT OF FAT | MADE FROM 100 LB. OF | GREEN CHEESE
| IN MILK | MILK | MADE FOR 1 LB.
| | | OF FAT IN MILK
------+-------------+------------------------+----------------
I | 3.35 | 9.14 | 2.73
II | 3.72 | 10.04 | 2.73
III | 4.15 | 11.34 | 2.70
IV | 4.74 | 12.85 | 2.71
V | 5.13 | 13.62 | 2.66
==============================================================
Table X shows that as the fat in the milk increases, the pounds of
cheese made from 100 pounds of that milk increases; but the amount of
cheese made for each pound of fat in the milk does not increase. This is
due to the fact pointed out in Table IX, namely, that as the fat
increases in the milk the casein does not increase in the rich milk in
proportion to the fat. From Tables IX and X this conclusion may be
drawn: that as the percentage of fat increases in the milk the more
cheese can be made from 100 pounds of that milk, but after the increase
in fat gets above 4 per cent the amount of cheese that can be made for
each pound of fat in the milk is decreased because the casein does not
increase in proportion to the fat. No exact statement of yield can be
made without first stating the moisture-content of the cheese. The
losses also must be considered.
Van Slyke[95] in the following Table XI shows the effect of the
fat-content of normal milk on the yield of cheese.
The moisture-content of all the cheeses is reduced to a uniform basis of
37 per cent. (See cut showing yield of cheese, Fig. 52.)
[Illustration: FIG. 52.--The figures represent the relative yield of
cheese containing different percentages of fat, but all have a uniform
content of 37 per cent water.]
TABLE XI
TABLE SHOWING THE EFFECT OF THE FAT-CONTENT OF
NORMAL MILK ON THE YIELD OF CHEESE
----------------+-------------+--------------+-------------------
PER CENT OF FAT | PER CENT OF | AMOUNT OF | AMOUNT OF CHEESE
IN THE MILK | CASEIN IN | CHEESE MADE | MADE FOR EACH
| THE MILK | FROM 100 LB. | POUND OF FAT
| | OF MILK | IN THE MILK
----------------+-------------+--------------+-------------------
3.00 | 2.10 | 8.30 | 2.77
3.25 | 2.20 | 8.88 | 2.73
3.50 | 2.30 | 9.45 | 2.70
3.75 | 2.40 | 10.03 | 2.67
4.00 | 2.50 | 10.60 | 2.65
4.25 | 2.60 | 11.17 | 2.63
4.50 | 2.70 | 11.74 | 2.61
4.75 | 2.80 | 12.31 | 2.59
5.00 | 2.90 | 12.90 | 2.58
----------------+-------------+--------------+-------------------
+213. Fat loss in cheese-making.+--The amount of solids lost in the whey
also affects the yield. The following table gives the amount of fat lost
in whey with normal milk containing different percentages of fat:
TABLE XII
SUMMARY SHOWING AMOUNT OF FAT IN MILK LOST IN
CHEESE-MAKING
=================================================================
GROUP | POUNDS OF FAT IN | POUNDS OF FAT LOST | PER CENT OF FAT
| 100 LB OF MILK | IN WHEY FOR 100 | IN MILK LOST
| | LB. OF MILK | IN WHEY
------+------------------+--------------------+------------------
I | 3 to 3.5 | 0.32 | 9.55
II | 3.5 to 4 | 0.33 | 8.33
III | 4 to 4.5 | 0.32 | 7.70
IV | 4.5 to 5 | 0.28 | 5.90
V | 5 to 5.25 | 0.31 | 6.00
=================================================================
Table XII shows that the percentage of fat in the whey is approximately
the same for milk high or low in fat. But the milk low in fat loses a
higher percentage of the total milk-fat in each 100 pounds of whey.
+214. Effect of bacterial-content of milk on yield of cheese.+--The
bacterial-content[96] of the milk influences the yield by affecting both
the moisture-content and the losses. If the milk is sour or has bad
fermentation, the losses will be increased because the curd cannot be
carefully handled, and the moisture cannot be incorporated to the extent
that it can in clean milk, without injury to the quality. The
proper-cooling of the milk in one instance increased the yield 0.3 pound
of cheese for each 100 pounds of milk. The more moisture that can be
incorporated into the cheese up to the legal limit, the greater the
yield.
+215. Factors affecting the moisture-content of Cheddar.+--The amount of
moisture that can be incorporated in a curd depends on several
factors.[97] The following increase the moisture-content control of the
cheese:
1. Cutting the curd coarse.
2. High setting temperature.
3. Low acid in the curd at time of removing whey.
4. Not stirring the curd with the hand as the last of the whey is
removed.
5. Slow pressure.
6. High piling of the curd in the cheddaring process.
7. Small amount of salt.
8. Holding the curd at low temperature after the whey is removed.
9. Large amount of rennet.
10. Cutting the curd hard.
The following factors decrease the moisture-content of the cheese:
1. Fine cutting.
2. Low setting temperature.
3. High acid in the curd at time of removing the whey.
4. Stirring the curd with the hand as the last of the whey is removed.
5. Fast pressure.
6. Low piling of the curd in the cheddaring process.
7. Large amount of salt.
8. Holding the curd at high temperature after the
whey is removed.
9. Small amount of rennet.
10. Cutting the curd soft.
From this discussion, it is evident that the yield of cheese from 100
pounds of milk increases with higher percentages of fat and casein in
the milk, with reduced losses of solids during manufacture, with the
absence of undesirable fermentations, and with the incorporation of
large amounts of water.
+216. Variations of the Cheddar process.+--The Cheddar process, as
already described, is widely employed in cheese factories. Many
varieties are found, however, and varietal names are used for such
products. A whole series of these forms are either locally or widely
made in England and taught in the English dairy schools. Some of these
varieties resemble the factory Cheddar product fairly closely; others
are clearly different products. A typical series of the variations as
developed in America will be considered.
In the commercial trade Cheddar cheese is usually designated by some
name which indicates its size. The size of the cheese is determined by
that of the hoops. The hoops vary both in diameter and height. The table
on the following page shows the usual sizes of the hoops and the weight
and name applied to the cheese.
+217. Cheddar-type cheese from pasteurized milk.+--Sammis and Bruhn[98]
have described a variation of the Cheddar process to overcome the
difficulties of making cheese from pasteurized milk. Such milk curdles in
very unsatisfactory manner unless some chemical is added to compensate
for the salts lost and to offset the other changes resulting from heat.
For this purpose, they found the use of hydrochloric acid satisfactory.
TABLE XIII
SIZE OF CHEESE HOOPS, WEIGHT, AND TERM APPLIED TO
CHEESE
========================================================================
DIAMETER OF | HEIGHT OF | WEIGHT OF | TERM APPLIED TO
HOOP | CHEESE | CHEESE | CHEESE
| | POUNDS |
---------------+-------------------+------------+-----------------------
6-7 in. | 7-8 in. | 9-11 | Young America
Tapers 5-7 in. | 10-14 in. | 10-16 | Long Horn
12-14 in. | 3½-4½ in. | 18-24 | Daisy or Picnic
14-15½ in. | 4-6 in. | 30-40 | Twin (two in same box)
14-16 in. | 4-7 in. | 35-40 | Flat
13½-15 in. | 10-12 in. | 40-50 | Cheddar
14-16 in. | 12-15 in. | 75-90 | Export
========================================================================
"The acidulation of milk with hydrochloric acid after pasteurization is
accomplished without difficulty or danger of curdling by running a small
stream of the acid, of normal concentration, into the cooled milk as it
flows from the continuous pasteurizer into the cheese vat. One pound of
normal-strength acid is sufficient to raise 100 pounds of milk from 0.16
percent to 0.25 percent acidity (calculated as per cent of lactic acid).
The amount of acid needed each day to bring the milk up to 0.25 per cent
acidity is read from a table or calculated from the weight of the milk
and its acidity, determined by the use of Manns's acid test (titration
with tenth-normal sodium hydrate and phenolphthalein). The preparation
of standard-strength acid in carboy lots for this work and the
acidulation of milk present no great difficulty to any one who is able
to handle Manns's acid test correctly.
"After the milk is pasteurized and acidulated three-fourths per cent of
first-class starter is added and the vat is heated to 85°. It is set
with rennet, using 2 ounces of rennet per thousand pounds of milk, so
that the milk begins to curdle in 7 minutes and is cut with three-eighth
inch knives in 25 minutes. All portions of the work after adding rennet
are carried out in an unvarying routine manner, according to a
fixed-time schedule every day. As soon as the rennet has been added the
cheese maker is able to calculate the exact time of day when each of the
succeeding operations should be performed, and the work of making the
cheese is thus simplified and systematized. It is possible that the
routine process here described may be varied somewhat with advantage at
different factories."
This cheese usually lacks characteristic Cheddar flavor or contains it
in very mild form. It therefore satisfies only those who seek very mild
flavored products. Efforts are now being made to find a flavor producing
substance or organism which will bring the flavor of this product more
nearly to that of typical Cheddar.
+218. Club cheese+ is known by a variety of trade names. It is made from
Cheddar cheese, so that it is especially liked by persons who care for
strong Cheddar flavor. It has a soft texture so that it spreads easily,
and is therefore much used for sandwiches. Well-ripened or old Cheddar
cheese is ground in a food chopper. The older the Cheddar, the stronger
will be the flavor of the club cheese. Cheese of good flavor should be
used. In order to do away with all lumps in the texture, it is sometimes
necessary to run the mixed cheese through the food chopper a second
time. While all lumps must be worked out, care should be taken not to
work the cheese so much that it will become salvy and sticky.
Usually a little pepper is added, to give the cheese a biting taste.
Some manufacturers add a great variety of substances, but these are not
necessary and destroy the flavor of the cheese.
Club cheese may be wrapped in tin-foil or put up in air-tight glass
jars. The latter practice, while more expensive, has the advantage of
making the cheese keep longer; but for local trade tin-foil is just as
satisfactory as glass. In filling the glass, care must be taken not to
leave any air spaces between the cheese and the glass, as this is likely
to permit the cheese to mold. A glass jar can be filled and air spaces
prevented by first smearing a very thin layer of cheese over the glass.
+219. The stirred-curd or granular process.+--The original practice as
brought from England and followed in the farm dairies before the
development of the factory system is now known variously as the
"stirred-curd" or "granular curd" process. With the introduction of the
cheese factory, as known to-day, this system was replaced by the Cheddar
cheese. The old farm process is still used on some farms and in a few
factories. As the name indicates, the curd for such cheeses is kept
stirred so that it remains in granular condition instead of being
allowed to mat as in the Cheddar process.
The early steps of the two processes are identical. They diverge at the
point at which in the factory Cheddar process the whey is drawn and the
curd is allowed to mat. In some factories the curd and part of the whey
are dipped into a curd sink. This allows the whey to escape more easily
and quickly. In the stirred-curd process, the pieces of curd are kept
separated by stirring and not allowed to mat. The whey is drawn off and
the stirring continued by hand. After stirring fifteen to twenty
minutes, the curd becomes so dry as not to mat easily. As soon as the
curd has reached this stage, the salt is evenly and thoroughly mixed
with it. More salt is added than in the Cheddar process because the curd
is more moist than Cheddar curd at the time of salting. The whey freely
separating carries away much of the salt. The quantity of salt to use
depends on the amount of whey draining from the curd. After salting, the
curd is allowed to cool, with occasional stirring to prevent the
formation of lumps. The advantage of the stirred-curd practice lies in
the shorter time required for making cheese and in the greater yield due
to increased water-content. It has several disadvantages, among them
being: (1) lack of control of undesirable fermentation; if gas organisms
are present, the cheeses more frequently huff than with the Cheddar
system; (2) there is more fat lost while stirring the curd, hence
quality and yield suffer; (3) the water is not so thoroughly
incorporated, which more frequently results in mottled cheeses; (4) the
body is commonly soft and "weak," shows mechanical holes, and cures too
rapidly. These faults are closely correlated with the presence of higher
percentages of water than in cheeses made by the Cheddar process. In
other words, the stirred-curd process usually produces a cheese with
higher water-content, hence more subject to the development of
unfavorable fermentation than the Cheddar cheeses.
+220. California Jack cheese+[99] is very similar to the stirred-curd or
granular process. This cheese was originally made in Monterey County on
the coast of California, about twenty-five years ago, in small
quantities, but after it was found to sell well other counties started
to manufacture it. As Monterey was the first county to make this
product, it was named "Monterey" cheese. In order to distinguish the
cheese made in other counties from this, it was suggested that it be
given a name and, consequently, it was called "Jack" cheese. This has
been accepted as its true name. The cheese is made mostly by Portuguese
and Italian-Swiss, although some of the best of the variety is now
manufactured near Modesto, California.
This cheese is adapted for manufacture on small dairy farms, where there
is inexpensive and scanty equipment. The smaller sizes of cheese are
made and ripened quickly. It has become widely used in California.
The cheese is made every morning, from evening's and morning's milk. The
former is put into the cheese vat at night, and morning's milk is added
as milking is going on. When the milk is all in the vat, it is
immediately warmed to 86° to 88° F. and rennet extract is added (when
milk has 0.2 to 0.21 of 1 per cent acidity) at the rate of 6 to 8 ounces
to 1000 pounds of milk. No coloring matter is used. It is ready for the
curd-knife in thirty to thirty-five minutes, its readiness being
determined the same as in making Cheddar cheese. The curd is first cut
lengthwise of the vat with the horizontal curd-knife and allowed to
stand until the whey rises over and partly covers the curd, when it is
cut again with the vertical curd-knife crosswise of the vat. It is then
hand-stirred, gently at first, and the stirring is finished with the
rake.
Either a steam-heating or self-heating vat is used (the steam-heating
vat is preferred) and temperature increased about one degree in five
minutes. The curd is heated to 98° F. in winter, and to 105° F. to 110°
F. in summer. After temperature is up, it is stirred occasionally with a
rake until the whey is drawn at 0.14 to 0.15 of 1 per cent acidity.
The curd is hand-stirred as soon as the whey is nearly drained off, and
raked to each side of the vat to drain more thoroughly, when it is
quickly stirred again to keep it from lumping or matting. Salt is now
added at the rate of 1½ pounds to 100 pounds of curd, and stirred in
thoroughly several times. During the salting process, cold water is
allowed to run under the vat, the hot water having been run off
previously.
Curd is put into cloths at a temperature of 80° to 85° F. No cheese
hoops are used. Two sets of press cloths are necessary; one set is ready
to use while the other is still on the cheese in the press. These press
cloths are about one yard square. The press cloths are all laid out
evenly one on top of the other, as many as there are cheeses. They are
then taken together and spread out over the top of a large, open tin
milk-pail, and pushed down in the center to the bottom of the pail, with
the edges hanging over the top. A common one-gallon lard pail is used to
measure the curd into the press cloths. A lard pail full will make a
cheese weighing six and one-half pounds, which is the popular size.
After a pailful has been put into the press cloth, the four corners are
caught up with the left hand, while with the right hand the curd is
formed round and the press cloth straightened and the other corners in
turn taken up. The press cloth is now taken up tight over the curd with
the left hand, while the cheese is given a rolling motion on the table
with the right hand, pressing at the same time to expel some of the
whey. This twists the press cloth tight over the curd, where it is tied
with a stout string. After fixing them all (as many as there are
cheeses) in this way, they are ready for the press.
The cheeses are pressed between two wooden planks, 12 inches wide, 1½
inches thick, by whatever length is required for the number of cheeses
to be pressed. One plank is nailed on supports at a convenient height
from the floor on a little slant for the whey to drain off better. The
cheeses in the press cloths are placed at the proper distance apart so
they do not touch. Then the other plank is put squarely over the top of
the cheese and levers about four feet long at an interval of five feet
are placed over this plank, from a cleat in the wall, on the other end
of which is placed a heavy weight of about 100 pounds, which acts as an
automatic pressure. The cheeses are left in the press until the next
morning, when they are taken out and put on the shelves in the
curing-room. The cheeses have no bandage or covering, and do not seem to
crock, and they form a very good rind.
The cheese is a sweet variety, weighs six and one-half pounds cured and
cures in about three weeks ready to ship, and sells at 16 to 25 cents a
pound wholesale. Most of the work seems to lie in forming and rolling
the curd in press cloths before pressing. Trouble is experienced by the
makers, especially in warm climates in summer, in not having the milk at
a uniform acidity when rennet is added. Great improvements could be made
in this cheese by using an acidimeter, paraffining and curing the cheese
in an even temperature, not much over 60° F.
Old and hard Jack cheese is also employed for grating and cooking, while
the fresh is used for the table.
+221. The washed-curd process+ has been developed in recent years
largely in the state of New York. In this method, a regular Cheddar curd
is made up to the time of milling. This curd is washed or soaked in cold
water during or directly after milling. The theoretical object of this
washing is to carry away bad flavors and to reduce over-development of
acidity by washing away all traces of whey. However, cheese-makers soon
found that it increased the yield and this led some to carry it to
extremes.
After the curd has been milled, it is covered with cold water. The
temperature of this water ranges from 50° F. to 70° F. The curd is
stirred in this water for various lengths of time according to the
judgment of the cheese-maker. This time varies from five minutes to one
hour. Sometimes the vat is partly filled with water and the curd milled
directly into the water. This process has certain advantages and
disadvantages.
The advantages are: if too much acid has developed in the curd, this
washing will reduce it so that the cheese will not be sour. Sometimes
when bad flavors are present in the curd, washing will tend to overcome
or remove them. Its disadvantages are: the larger yield due to excessive
soaking tempts the makers to soak curd beyond the time needed to relieve
the initially sour condition. Curd soaked in this way produces cheeses
containing percentages of water so high as to lower their quality. This
increases the yield sometimes as much as 3 to 5 per cent. Such a cheese
is very soft in texture and does not cure like a Cheddar cheese which
has not been washed. Part of the lactic acid, milk-sugar[100] and the
inorganic salts are removed by this washing. A washed-curd cheese will
sometimes rot, due to the activity of the putrefactive bacteria, and to
the lack of the restraining effect of the lactic acid-forming bacteria.
Some washed-curd cheeses are so soft that they will not retain their
normal shape.
A washed-curd cheese is never sour because the milk-sugar and lactic
acid have been removed by washing.
+222. English dairy cheese.+--In some localities cheeses are still made
on the farms. These are mostly produced after the stirred-curd process,
hence are soft-bodied and open-textured. They usually weigh ten to
twelve pounds and are three to four inches thick and twelve inches in
diameter.
+223. Pineapple cheese.+--This variety derives its name from the fact
that the cheeses are made in about the size and shape of a pineapple.
The curd is made after the Cheddar process from either whole milk or
partly skimmed milk. It is pressed in molds shaped like a pineapple. The
cheeses are then hung in nets to give the checked appearance on the
surface. They are rubbed with linseed oil to prevent the surface
cracking, and finally are shellacked.
+224. Leyden.+--Among specialties, a cheese called Leyden originating in
Holland is made in Michigan and New York. This is a part skim cheese
heavily spiced with caraway seed. The ripe cheese is colored red as it
goes to market.
+225. Cheddar cheese with pimientos.+--Recently some Cheddar cheeses
have been made with pimientos added. This gives a mixture of
characteristic Cheddar and pimiento flavors, which seems to be desired
by some persons. An ordinary Cheddar curd is made and the pimientos
added just before salting. The pimientos are ground rather coarsely and
then added to the curd together with the liquid which was with the
pimientos in the can. The pimiento should be thoroughly and evenly
mixed with the curd to insure a uniform distribution and mottled color
in the cheese. The salt is then applied. The remainder of the process is
the same as for ordinary Cheddar cheese.
+226. Sage cheese+ is a product flavored from the leaves of the ordinary
garden sage. It is made by two methods: one, in which the sage leaves
are used, and the other, in which a part of the curd is colored to
imitate that given by the sage leaves, and sage oil or tea is used to
give the flavor.
In the leaf method, a regular Cheddar cheese curd is made up to the time
of salting. Just before the salt is added, sage leaves are mixed with
the curd. The leaves should be dried and freed from stems and other
coarse particles and the leaves themselves broken up rather finely. The
leaves are then added at the rate of 3 ounces for every 1000 pounds of
milk. Care must be exercised to see that the leaves are evenly mixed
through the curd or an evenly mottled cheese will not result. The salt
is then added. This sequence seems to increase the absorption of the
flavor by the curd.
If these cheeses are consumed as soon as well cured, no fault can be
found. On the other hand, if they are held for any length of time,
yellow areas form about each piece of sage leaf; the leaves decay
rapidly and spoil the cheese. This method gives a very true flavored
sage cheese, the only objection being that it cannot be held in storage
for any length of time without a marked deterioration.
In the other method of making sage cheese, either a vat with a movable
partition or a large and a small vat must be used. In many cases the
receiving can is used as the small vat. After the milk is properly
ripened and ready to set, one-sixth to one-seventh of the milk is put
into the small vat. To this small vat, green coloring matter is added.
Juice from the leaves of corn, clover, or spinach was formerly used as
coloring. Consequently the manufacture of sage cheese by this method was
limited to the seasons of the year when these leaves could be obtained.
Now, however, the dairy supply houses have a harmless green color paste
which is much cheaper and can be secured at any season of the year. The
amount of color paste to use will vary from 30 to 35 c.c. for every 1000
pounds of total milk. This should be added to the small vat of milk. It
gives a green milk and later a green curd.
Both vats are worked along together, until the time for removing the
whey. Then the partition in the vat is removed or the small vat is mixed
with the large one. The green curd should then be evenly mixed with the
white one or an even green mottled cheese will not result. The curds
should not be mixed until they are well firmed or the white curd will
take on a greenish cast and spoil the appearance of the cheese.
After the whey is removed, the curd is allowed to mat as in ordinary
Cheddar but care must be exercised to pile the curd so that it cannot
spread or "draw" out. If it does draw out, the small green spots will be
stretched out and large blotches or patches of green will be the result.
The cheese-maker must watch the curd closely or he may not secure the
much desired small green mottles. When the curd is well matted, it is
milled as in Cheddar. Just before the salt is added, the sage extract is
applied to the curd.
The sage extract can be obtained from dairy supply houses, or a sage
tea can be made by steeping the sage leaves. In many cases the
commercial extract gives the cheese a strong disagreeable flavor, but
not a true sage flavor. The sage tea gives a flavor more like that of
the leaves themselves. Too much of the extract or the leaves will give a
very rank flavor. The sage extract can best be put on the curd by means
of a sprayer or atomizer with which it can be evenly sprayed over the
entire surface. The extract should be applied two or three times and the
curd well stirred after each application. The amount of the extract to
use depends altogether on its strength; an ounce of the extract or three
ounces of sage tea to 1000 pounds of milk is about the correct amount.
After the extract has been added, the salt is used at the same rate as
with a normal Cheddar curd and the sage curd is carried along the same
as a Cheddar.
This extract method gives a sage cheese mottled with small green spots
which somewhat resemble the green of sage leaves. A cheese made in this
way can be held for a long time, as nothing has been added which can
decay. The only objection to this method is that the sage extract may
not give a true sage flavor. Therefore, the maker must try to obtain the
best extract possible or make his own from the sage leaves.
+227. Skimmed-milk Cheddar cheese.+[101]--The process of making
skimmed-milk cheese after the Cheddar process is varied with the amount
of fat left in the milk. Before attempting to make skimmed-milk Cheddar,
one should become familiar with the process for whole-milk Cheddar.
Skimmed-milk cheeses are usually highly colored.
When part skimmed-milk cheese is manufactured, there is often
difficulty in getting the milk in the vat to test the desired percentage
of fat. Some cheese-makers skim all the milk and then put in the desired
amount of cream. This practice seems wasteful, not only because of the
cost of separation, but because the fat will not mix easily with the
milk but will tend to float on the surface. If the fat floats, there
will be a large loss. After a very few trials an operator can tell about
how much of the whole milk must be skimmed in order to have the mixed
skimmed-milk and whole milk test the desired percentage of fat. The
necessary percentage of fat in the mixed milk to produce cheese of a
certain grade can be determined by testing the cheese by the Babcock
test. (See Chapter XIX.)
+228. Full skimmed-milk Cheddar cheese.+--In the summer there is not
much demand for full skimmed-milk cheese, but it is made in large
quantity in winter. The method of manufacture is as follows:
Skimmed-milk as it comes from the separator is at a temperature of about
88° to 90° F.; it is ripened and set at this temperature. It is ripened
rather highly on the acid test, from 0.18 to 0.20 of 1 per cent, and to
correspond on the rennet test which will not be many spaces. In about
twenty-five to thirty minutes it is coagulated ready for cutting. The
curd of skimmed-milk cheese is cut a little softer than is that of
whole-milk cheese. Milk is usually set at 88° to 90° F. The curd is not
ordinarily cooked above this temperature. If the milk was 84° to 86° F.
when set, then the curd should be raised to 88° to 90° F. The curd firms
in the whey very rapidly. When firm enough, it should have a slight
development of acid. On the acid test it should show 0.17 to 0.19 per
cent, and on the hot iron 1/8 to ¼ of an inch. The milk should be ripe
enough or starter enough should have been used, so that the acid will
continue to develop in the "pack" very rapidly. During the cheddaring
process the curd is piled more rapidly and in higher piles than is
customary with whole-milk cheese. This is necessary to incorporate or
assimilate a large percentage of water or whey in the cheese. Therefore
the process of skimmed-milk Cheddar cheese is much shorter. More acid is
developed with the skimmed-milk than with the whole-milk cheese because
it seems necessary to develop proper texture. If the acid is not
developed sufficiently, the cheese will be very rubbery and cure very
slowly, in which case bad fermentation and flavor may and often do
develop. The curd is turned, piled or cheddared in the vat until it
begins to become meaty and fibrous. If there is danger of too much acid,
the curd may be rinsed off with water. It is then milled and salted at
the rate of 1 or 1¼ pounds of salt to the curd from each 1000 pounds
of milk. The remainder of the process is the same as that for making
whole-milk cheese.
+229. Half skimmed-milk Cheddar cheese.+--No definite directions can be
given for the manufacture of part skimmed-milk cheese, because the
process varies with the amount of fat left in the milk. As the fat is
decreased, the process becomes more like that for making full
skimmed-milk cheese; as the fat is increased, the process becomes more
like that for whole-milk cheese. However, the process of making half
skimmed-milk cheese is about midway between the two. The milk is ripened
more than it would be for whole-milk cheese, usually until it tests from
0.15 to 0.17 of 1 per cent acid. The curd is coagulated and cut the same
as for the other skimmed-milk cheeses. It is cooked to a temperature
just sufficient to firm the curd, usually from 94° to 96° F. The lower
the temperature at which the curd can be cooked and yet become firm,
the better is the texture of the cheese. When the curd has firmed
enough, or when sufficient acid development, from 0.15 to 0.17 of 1 per
cent, has taken place, the whey is removed. The curd is then turned,
piled or cheddared. A skimmed-milk curd may be piled much more rapidly
than a whole-milk curd without danger of injuring it. When the curd
becomes meaty or fibrous, it is milled. It should be salted at the rate
of 1¼ to 2 pounds of salt to the curd from each 1000 pounds of milk.
The remainder of the process is the same as that for making whole-milk
cheese.
The cheese-maker should observe the following points when making
skimmed-milk cheese: (1) Have clean-flavored sweet milk; (2) use
clean-flavored commercial starter; (3) ripen the milk sufficiently, but
not too much; (4) firm the curd at as low a temperature as possible; (5)
have the curd properly firmed when the whey is drawn; (6) cheddar the
curd faster than the curd from whole milk; (7) make the cheeses all the
same size; (8) keep the cheese neat and clean in the curing-room.