processing. It is especially satisfactory for vegetables and meat, since a
much higher temperature than that of boiling water is maintained during
the processing period. The higher temperature also makes it possible to
process foods in a shorter time. However, it is thought by some that the
flavor of foods canned above 212 degrees F. is inferior to that canned at a
lower temperature. Moreover, the pressure cooker is a more expensive device
than either of the other two.
QUESTIONS
Why should processed jars, covers, and rubbers remain in boiling water
until just ready for use?
Why not touch the inside of jars and covers with the fingers?
Why should berries and small fruits be washed before hulling or stemming?
Why should decayed or bruised spots on fruits be removed completely before
canning the fruit?
Why is it that the cold pack method of canning is safer from the
standpoint of processing than the open kettle method?
Why should the jar containing fruit that is to be processed by the
cold pack method be filled to 1/4 inch of the top with sirup rather than
to overflowing?
Why should the covers of jars not be sealed tightly before placing in the
kettle or steamer used for processing?
Why is it unnecessary and undesirable to dislodge air bubbles in jars
containing food processed by the cold pack process?
When food is processed by immersing the jars in boiling water, why should
the water extend above the covers of the jars to a depth of one inch?
LESSON CLXVIII
PROCESSING WITH MUCH SUGAR--PRESERVES, JAMS, AND CONSERVES
EXPERIMENT 93: THE USE OF SUGAR AS A PRESERVATIVE.--Place 2 thin slices of
fresh fruit in a sauce dish. Sprinkle one of the slices generously with
sugar. Set the sauce dish aside for at least 24 hours. Examine. What
change has taken place in the fruit without sugar? What has caused the
change? Compare the sugared fruit with that without sugar. What conclusion
can be drawn concerning the use of sugar in preserving fruit?
PRESERVES
Sugar was mentioned as one of the preservatives used in the preservation
of food (see _The Principles of Preserving Food_). Sugar in large
quantity is unfavorable to germ life and hence is a most effective
preservative. _Preserves_ are made by cooking fruit in a thick sirup
as in the _Method of Canning_ (_a_) Open Kettle. A large
quantity of sugar is desirable as far as preservation is concerned; but
for flavor less sugar is usually to be preferred. Only a few fruits are
better when preserved with considerable sugar. Fruits best adapted for
preserving are strawberries, sour cherries, sour plums, quinces, currants,
and raspberries. For preserves, use 3/4 to 1 pound of sugar for 1 pound of
fruit. The less quantity of sugar should be used for peaches, plums,
quinces, currants, and raspberries; the greater quantity, for strawberries
and cherries. Use the quantity of water given in _Method of Canning_
(_a_) Open Kettle. Cook and seal as canned fruit.
JAMS
Jam is made as follows: Clean the fruit. If large fruits are used, pare or
peel them and cut into small pieces. If small fruits,--berries or grapes,
--are used, mash them. Cook the fruit in as little water as possible. When
the fruit is soft, measure it and add the sugar,--use 3/4 to 1 part of
sugar to 1 part of cooked fruit. Cook until thick, stirring to prevent
burning. Test the thickness by dropping from a spoon. If it falls in heavy
drops, the jam is sufficiently cooked. Pour into sterilized jelly glasses.
Cover the glasses with clean cloth or paper and set aside to cool and
stiffen. Melt paraffin. Pour it (hot) over the cold jam. Allow the
paraffin to harden and then cover the glasses with the lids. Wipe the
outside of the glasses, label, and store.
Fruit that is too soft or too ripe for canning or preserving may be used
for making jam.
MARMALADES
Marmalades are made much as jams. However, usually only the pulp and
juices of fruits are used. The fruit is first cooked, and the skins and
seeds removed before adding the sugar. In Orange Marmalade, the rind is
used.
CONSERVES
Conserves consist of a combination of two or more fruits. Nuts and other
materials are sometimes added. Conserves may be prepared as preserves,
_i.e._ cooking the ingredients with sugar, until thick; or as jam,
_i.e._ cooking the ingredients until tender, then adding the sugar
and cooking until thick. It is thought by some that the latter method
produces a finer flavor; it makes a product less tough and less sticky. In
the special recipes for conserves given in this text, the latter method is
followed.
ORANGE MARMALADE (I)
1 dozen oranges
1 grapefruit
6 lemons
Sugar
Weigh the fruit, slice it. To each pound of fruit add 1 quart of cold
water. Let the mixture stand for 24 hours. Then cook slowly for 2 hours.
Weigh the cooked fruit. Add an equal weight of sugar. Cook for 1 hour or
until it stiffens. Pour into sterilized jelly glasses, seal, and cover as
directed for Jams.
ORANGE MARMALADE (II)
1 dozen oranges
3 pounds sugar
2 quarts rhubarb
Rind of 6 oranges
Wash the fruit. Slice the oranges and cut the rhubarb into pieces. (Do not
peel the rhubarb.) Cook the oranges and rhubarb for 30 minutes. Add the
sugar and cook slowly for 2 hours or until thick. Pour into sterilized
glasses. When cool, seal and cover as directed for Jams.
CARROT MARMALADE
1 pound carrots
3 cupfuls sugar
2 lemons
1/2 teaspoonful salt
Wash, scrape, and chop the carrots. Extract the juice from the lemons. Put
the carrots and lemon rinds through a food chopper, cover them with water,
and cook until tender. Add the lemon juice, salt, and sugar to the cooked
mixture. Cook until it is thickened. Turn into sterilized jelly glasses.
Let stand until cool. Then cover with melted paraffin.
STRAWBERRY AND PINEAPPLE CONSERVE
Use equal quantities of strawberries and shredded pineapple. Cook the
shredded pineapple in the least possible quantity of water. When tender,
add the strawberries and cook until they are soft. Measure the fruit and
add three fourths as much sugar as fruit and a small quantity of salt.
Cook until thick (see _Jams_). Pour into sterilized glasses. Seal and
cover as directed for Jams.
CRANBERRY CONSERVE
1 quart cranberries
1 1/2 cupfuls water
1/4 pound raisins
1/2 pound California walnuts, chopped
1 orange,--juice and grated rind
1 1/2 pounds sugar
1/2 teaspoonful salt
Wash the fruit. Cook the cranberries in the water until the berries burst.
Strain. Add the remaining ingredients and cook 25 minutes or until the
mixture is thick (see _Jams_). Pour into sterilized glasses. When
cool, seal and cover as directed for Jams.
GRAPE CONSERVE
1/2 peck grapes
2 oranges,--juice and rind
2 lemons,--juice and rind
1 cupful chopped nuts
Sugar
1/2 teaspoonful salt
Wash the fruit. Remove the grapes from the stems; remove the skins from
the pulp. Cook the pulp until soft; strain, to remove the seeds. Place the
strained pulp and skins in a preserving kettle. Extract the juice from the
oranges and lemons, then put the rinds through a food-chopper. Add the
lemon and orange juice and rind to the grape mixture and cook for 1 hour.
Measure the mixture. Then add an equal quantity of sugar and the nuts and
salt. Continue cooking until thick (_see Jams_). Pour into sterilized
glasses. When cool, seal and cover as directed for Jams.
APRICOT CONSERVE
1 pound dried apricots
1 1/2 quarts water
Sugar
2 pineapples _or_
1 large can shredded pineapple
1/2 teaspoonful salt
Wash the dried apricots and soak them in the water. In the water in which
they were soaked, cook the apricots until tender. Press through a
colander. If fresh pineapples are used, shred them and cook, in as little
water as possible, until tender. Combine the cooked fruits and measure.
Add 1/2 as much sugar and the salt. Cook until thick (see _Jams_).
Pour into sterilized glasses. When cool, seal and cover as directed for
Jams.
PLUM CONSERVE
1 pound (1 1/2 dozen) plums
1/4 cupful chopped nuts
1 cupful seeded raisins
2 oranges
1 cupful water
1 1/4 cupfuls sugar
1/2 teaspoonful salt
Wash the plums, stone, and cut into pieces. Extract the juice from the
oranges. Put the rind through a food chopper. Mix the plums, raisins,
orange rind, and water. Simmer until the fruits and peel are tender. Add
the orange juice, sugar, nuts, and salt, and continue cooking until the
mixture has the consistency of marmalade. Pour into sterilized glasses.
When cool, seal and cover as directed for Jams.
QUESTIONS
How do Preserves differ from Canned Fruit?
How does Jam differ from Preserves?
How does Jam differ from Fruit Sauce?
Why does Jam "keep" better than Fruit Sauce?
Give method of sealing Canned Fruit and method of sealing Jam. Explain why
different methods are used.
LESSON CLXIX
PROCESSING WITH MUCH SUGAR--JELLIES
EXPERIMENT 94: PECTIN IN FRUIT JUICE.--Put a few grapes, slices of apple,
or cranberries in a small saucepan, and add enough water to cover and cook
until the fruit is tender and soft enough to mash. Strain the cooked fruit
through cheese-cloth.
Put 1 teaspoonful of the extracted fruit juice in a saucer, add an equal
quantity of alcohol. [Footnote 126: Either grain (ethyl), wood (methyl), or
denatured alcohol may be used. _Both wood and denatured alcohol are
poisonous_. If they are used for testing, they should be handled and
stored away with caution.] Mix by gently rotating the saucer. Let the
mixture stand for 5 minutes. Then examine. What change has taken place in
the fruit juice?
The formation of a solid mass in the mixture of fruit juice and alcohol
which has stood for 5 minutes indicates that the fruit juice contains
pectin,--a vegetable gelatine.
EXPERIMENT 95: PECTIN IN THE INNER PORTION OF ORANGE OR LEMON PEEL.--Cut
away the yellow portion from orange or lemon rind. Cut or chop the white
portion of the rind in small pieces. Cover with water and soak several
hours or overnight. Then cook slowly for 1/2 hour. Strain and set aside to
cool. To 1 teaspoonful of this liquid add an equal quantity of alcohol,
and proceed as in Experiment 94. Does the lemon or orange rind contain
pectin?
THE PRINCIPLE OF JELLY MAKING.--When the juices of certain fruits are
extracted and cooked with sugar, the mixture stiffens when cool. This
property of stiffening is due to the presence in fruit of two materials,--
a certain carbohydrate, called _pectin_, and an acid. Pectin is like
starch in that it stiffens when cold; but like sugar, in that it is
soluble. Not all fruits contain pectin.
Jelly is most easily prepared from fruits which are rich in pectin and
contain some acid. Unless pectin is contained in the fruit, the addition
of sugar to fruit juice will not cause the juice to jelly. But jelly may
be made from a fruit lacking in pectin, if it is combined with a fruit
rich in pectin.
Certain fruits contain pectin, but are lacking in acid, hence are not good
for jelly making. These fruits can be used for jelly, however, if acid is
added.
SELECTION OF FRUITS FOR JELLY MAKING.--For jelly making, choose fruits
which contain considerable pectin and some acid. The fruits should be
fresh and not over-ripe. Some "green" fruits make fine jelly. Currant,
crabapple, grape, apple, and plum are good jelly-making fruits.
If it is desirable to use a fruit containing little pectin, as
strawberries, add a fruit rich in pectin, as currants. If about 10 per
cent of the fruit which contain much pectin is added to the other fruit,
the flavor of the foundation fruit is not much altered.
If it is desired to use a fruit containing pectin but deficient in acid,
as sweet apple and quince, add tartaric or citric acid. Since the acidity
of fruits varies, no definite quantity of acid can be stated. It has been
suggested [Footnote 127: See University of Illinois Bulletin, "Principles
of Jelly Making," p. 249.] that enough acid should be added to make the
fruit juice about as acid to taste as good tart apples. At least one
teaspoonful of acid is required for one quart of fruit juice. Dissolve the
acid in the fruit juice, then taste the mixture. If necessary, add more
acid to produce the acidity indicated above. Jelly may be prepared from
strawberries, peaches, and pears by the addition of these acids, but the
flavor is somewhat impaired.
The suggestion has been made also [Footnote 128: _Idem_, p. 25.] that
the inner white portion of lemon or orange peel be used as a source of
pectin with fruit deficient in pectin. Remove the yellow portion of the
rind, put the white portion through a food chopper, and soak in water for
several hours or overnight. Then cook slowly for several hours. Strain out
the solid portion. Add the liquid to the fruit juice deficient in pectin
and use for jelly making. The rind of lemons and oranges may be dried for
use in jelly making. When desired for use, soak and cook as directed
above.
GENERAL METHOD OF JELLY MAKING
Wash and pick over the fruit; remove the stems, but use the skin and seeds
and thus retain as much of the fruit as possible. The skin of fruit
usually adds color to jelly. If large fruit is used, cut it in pieces.
Cook the fruit slowly in water. Use very little water for juicy fruits,
such as currants and raspberries,--_1 cupful of water to 4 or 5 quarts
of fruit_. Crush the fruits during cooking.
To cook large fruits requires water. A general proportion is _half as
much water, by measure, as prepared fruit_. A little less water may be
used for peaches and plums and a little more for winter apples. A fair
estimate is 3 quarts of strained juice from 8 quarts of fruit and 4 quarts
of water. If the quantity of juice is greater than this, it should be
boiled down to 3 quarts before adding the sugar.
When the fruit is cooked until it is very soft, it is ready for straining.
For straining, make a bag of double cheesecloth or flannel. Wring the
jelly bag out of hot water and suspend it from a strong support. Pour the
cooked fruit into the bag and let the juice drip into a bowl. If
transparent jelly is desired, do not press the juice through the bag; let
the juice drip for several hours or overnight.
Measure the clear fruit juice and heat it. The time of cooking depends
upon the per cent of pectin and the acidity of the juice; the more pectin
and acid, the less the time of cooking. The time varies from 8 to 30
minutes. Skim the juice when necessary. While the juice is cooking,
_measure three fourths as much sugar_ [Footnote 129: The quantity of
sugar used in jelly making depends upon the quantity of pectin in fruit
juice,--the more pectin, the more sugar. A most satisfactory method of
determining the quantity of pectin and consequently the quantity of sugar
to use with fruit juice is suggested by the Bulletin of the National War
Garden Commission. The test follows: To a tablespoonful of fruit juice
which has been boiled and cooled, add 1 tablespoonful of alcohol (see
footnote 126.). Mix by gently rotating and then let stand. If a solid mass
forms, _use equal parts of fruit juice and sugar_. If 2 or 3 masses
form, _use 2/3 to 3/4 as much sugar as juice._ If several small solid
particles form, _use 1/2 as much sugar as juice_. If no solid
particles form, the fruit juice should be enriched by the addition of some
pectin-rich fruit juice.] _as fruit juice_ and heat the sugar. For
currants and green or under-ripe grapes, use equal quantities of sugar and
fruit juice. Add the hot sugar to the boiling sirup and cook. The
following are _tests for sufficient cooking of jelly._
(_a_) Coats the spoon.
(_b_) Falls from the spoon in heavy drops. [Footnote 130: Two drops
forming side by side along the edge of the spoon has been found to be a
reliable test.]
(_c_) Stiffens when dropped on a cold dish and allowed to cool.
The first two tests are more satisfactory than the last, since the cooking
process may be carried too far while the "test-jelly" is cooling.
Seal as Jam or shred paraffin and place it in the bottom of sterilized
jelly glasses. Pour the hot jelly into the glasses and set aside to
stiffen. Then cover and store. It is well to store jelly in a cool, dry,
and dark place. The color of fruit sometimes fades when kept in a light
place.
Long cooking of pectin changes it into substances which do not have the
property of jellying, hence, make jelly in as short a time as possible.
The purpose of heating the sugar is to hasten the process of jelly making.
The addition of cold sugar would cool the mixture and thus prolong the
process.
The addition of too much sugar is often the cause of unsuccessful jelly
making. Crystallization of the sugar from the jelly may result from an
excess of sugar.
The _fruit pulp left in the jelly bag_ should be utilized. Marmalade
may be made from it, or more jelly can be prepared from it. To accomplish
the latter, add water to the fruit pulp (enough to cover), mix, and heat
slowly until the boiling point is reached. Strain and prepare jelly from
the juice. However, more cooking of the juice before the sugar is added is
required for the second extraction, since the juice contains so much
water. The juice extracted for a third time from most fruits will contain
enough pectin for jelly making. It has been found that more desirable
jelly can be obtained by this method than by pressing the juice from the
bag and thus obtaining what is termed "second quality" jelly.
FRUIT JUICES WITHOUT SUGAR.--Extract the juice from fruit as directed in
_General Method of Jelly Making_. Do not add sugar to the juice. Can
it as directed in (_a_) or (_b_).
(_a_) Reheat until the boiling temperature is reached, then pour into
sterilized jars. Fill to overflowing and seal.
(_b_) Place the juice in sterilized jars. Partially seal and place in
a water bath having the water reach the neck of the jar. Let it cook at a
simmering temperature from 20 to 30 minutes. Remove from the water bath,
and seal securely.
In the winter time or when desired for use, this fruit juice may be made
into jelly as directed in _General Method of Jelly Making_, or it may
be sweetened, diluted if necessary, and used as a beverage. This method of
preserving fruit juice is especially desirable when there is a scarcity of
sugar.
[Illustration: FIGURE 92--THE COMPOSITION OF FRUITS AND FRUIT PRODUCTS.
(Revised edition.)]
QUESTIONS
Note the difference in the quantity of carbohydrates in Canned Fruit and
Fruit Jelly (see Figure 92). What kind of carbohydrate is present in
greatest quantity in these foods?
To what is the difference in flavor of Canned Fruit and Fruit Jelly
largely due?
What is the chief difference in the processes of jam making and jelly
making?
What is the result if too much sugar is used in jelly making?
What is the result if jelly is cooked too long?
Note the difference in the methods of sealing jams and jellies. Explain.
LESSON CLXX
PROCESSING WITH VINEGAR AND SPICES--RELISHES
SPICES AND VINEGAR ARE PRESERVATIVES OF FOODS. Not all spices, however,
have equal preservative power. It has been found that cinnamon and cloves
aid in food preservation, but that pepper and ginger have very little, if
any, preservative power. In the lesson on _Flavoring Materials: Food
Adjuncts_, it was mentioned that spices and condiments should be used
sparingly in the diet, hence spiced fruits and pickles should have only
occasional use. There is no doubt that lemon juice or other tart fruit
juices are better sources of acid-satisfying materials than vinegar.
SPICED PEARS
1/2 peck pears
3 pounds sugar
1 pint vinegar
1/2 ounce ginger root
Rind of 1/2 lemon
Whole allspice
Stick cinnamon
Whole cloves
Cut the pears in halves, remove the seeds, and pare. Into each piece of
pear stick two or three cloves. Make a sirup of the vinegar and sugar.
Divide the cinnamon, allspice, and ginger into two parts, tie in cheese-
cloth bags, and add to the sirup. When the sirup begins to simmer, add the
pears and lemon rind; bring to the boiling point, remove from the fire,
and turn into a stone jar. Cover and stand in a cool place overnight. Next
day bring the mixture to the boiling point, again place in the stone jar
and stand overnight. The following day heat as before. Do this for five
consecutive days. The last day, remove the fruit from the sirup, heat the
sirup and evaporate it until there is just enough to cover the fruit. Add
the fruit to the hot sirup, heat to the boiling point, then put in stone
or glass jars or tumblers.
The pears may be finished in one day as follows: Cook the fruit until
tender, then remove it, evaporate the sirup, add the fruit, reheat again,
and finish as above. Fruit prepared by the first method has a finer
flavor.
TOMATO CATSUP
12 ripe tomatoes
2 large onions
2 green peppers
2 tablespoonfuls salt
4 tablespoonfuls brown sugar
2 tablespoonfuls ginger
1 tablespoonful cinnamon
1 tablespoonful mustard
1 nutmeg grated
1 pint vinegar
Peel the tomatoes and onions. Chop the onions and peppers fine. Cook all
the ingredients together for 3 hours, or until soft and broken. Stir
frequently. Bottle and seal while hot. The mixture may be strained before
bottling.
CELERY SAUCE
20 large ripe tomatoes
6 large onions
4 large stalks celery
3/4 cupful sugar
1 large red pepper
4 tablespoonfuls salt
2 cupfuls vinegar
Chop the vegetables, add the salt and vinegar, and cook for 2 hours. Then
add the sugar. Allow it to reach the boiling point again. Turn into
sterilized bottles or jars, and seal.
OIL PICKLES
2 dozen small cucumbers
2 dozen small onions
1/2 cupful olive oil
1/4 cupful sugar
1 pint vinegar
1/3 cupful salt
1/4 cupful mustard seed
1 pint vinegar
1 teaspoonful celery seed
Scrub the cucumbers. Cut them (without paring) into thin slices. Wash and
cut the onions into thin slices. Mix the salt with these vegetables (to
extract moisture), and let the mixture stand over night. Then drain the
moisture from the vegetables so that the vinegar may not be diluted.
Mix the remaining ingredients. Pour the mixture over the onions and
cucumbers. Mix well, cover, and set aside for a few hours. Then pour into
sterilized jars. Fill the jar with liquid. (If necessary, more vinegar may
be used.) To drive out the air, place the jars (with covers loosely
adjusted) in a water bath at simmering temperature (180 degrees F.) and
heat at this temperature for 15 minutes. Remove from the water bath and
seal.
TO SEAL BOTTLES.--Melt together, over hot water, equal parts of
shoemaker's wax and resin. When liquefied, dip the tops of corked bottles
into it. Corks in bottles may be dipped also in hot paraffin. Dip several
times.
QUESTIONS
What is the objection to excessive use of spiced foods?
Name some substitutes for pickles. Why is an excessive or continuous use
of pickles objectionable in diet?
LESSON CLXXI
CANNED VEGETABLES
MICROORGANISMS IN THE SPORE FORM.--Many microorganisms are destroyed by
heating them for a few minutes to boiling temperature. However, some
microorganisms have a peculiar power of retaining life under most adverse
conditions. When subjected to extreme heat or cold, intense drying, or
when there is lack of food, certain microorganisms assume a spore form,
_i.e._ they cease growing and reproducing, and are able to undergo
conditions which would readily kill microorganisms in the active form.
Some microorganisms in the spore form are able to resist the temperature
of boiling water for an hour or longer. Then as soon as the adverse
conditions mentioned above are removed, the microorganisms assume active
form and begin to grow and reproduce. In the growing state, their
destruction is not so difficult.
Some of the microorganisms in certain foods, especially vegetables and
fruits grown in a dry season, are capable of spore formation. When
microorganisms in spore form do exist in foods that are to be canned, or
the microorganisms change into spore form during the canning process, the
microorganisms may not be destroyed by the time the ordinary process of
canning is completed. If such is the case, when the canned foods are
cooled and the conditions are favorable for growth, the microorganisms
assume active form, begin to grow, and cause the decomposition of food.
Twenty-four hours is sufficient time for the microorganisms to change from
the spore to the active form. Hence the canned foods must be heated again,
if they are to be preserved. For foods difficult to process (for the
reason given above) processing should be carried on for three successive
days. This is called _intermittent processing_.