12. On first thought it would seem as if there is very little to guide
the housewife in the selection of eggs, it being extremely difficult to
tell from their external appearance whether or not they are fresh or
stale. As a rule, she must trust largely to the honesty of the person
from whom she buys eggs. Still she need not depend entirely on the
dealer's word, for, at least to a certain extent, there are ways in
which she may judge the quality of eggs. Because of the great value of
eggs as a food and for cooking purposes, it is important that the
housewife make use of all available information on this matter and, in
addition, become familiar with the trade practices in the egg industry.
13. MARKETING OF EGGS.--As is generally known, hens lay a large number
of eggs in the spring of the year, but they do not lay readily in the
cold winter months; and not alone are the greatest quantities of eggs
produced in April and May, but those laid at this time are of the best
quality. Because of this condition and in order that the demand during
the time of scarcity may be supplied, it is necessary that a
considerable number of eggs be preserved when they are comparatively
cheap and abundant. Also, in the preserving of eggs for future use, it
is of the greatest importance that they be kept in the best possible
condition and manner, so that when they are used, months after they are
laid, they may be as good as it is possible to have them.
The advance made in storage and transportation methods in recent years
has done much toward making the egg supply uniform all the year around.
Not long ago, because of inadequate means of storage and shipping, eggs
were sold only a short distance from the place where they were produced.
However, with the coming of cold storage and improved methods of
shipping, eggs have been changed from a perishable and more or less
seasonable food to a staple one. Now it is possible to collect them in
large quantities, to keep them for a considerable time before selling
them, and to ship them long distances. To safeguard the public, though,
authorities have set a time limit for the storage of eggs, the legal
time they may be kept being 8 months. By this is meant that eggs placed
in the warehouse in May must be released or sold in December; whereas,
those stored in June must be released no later than January.
14. Eggs that have been kept too long in storage are characterized by a
musty odor and flavor, the breaking of the yolk and its mixing with the
white, and a watery condition of the white. Such eggs, of course, cannot
be sold legally. Those which may be placed on the market are graded
according to their freshness, cleanliness, size, cracks, and color. With
the exception of their freshness, these points can be readily told from
the appearance of the eggs; but, in order to determine whether an egg is
fresh or not, it is generally put through a process known as _candling_,
by which the interior condition of the egg can be ascertained.
In the grading of eggs, all those of the best size, color, and condition
are sold under a particular trade name and bring a high or a low price,
according to the grading. Others that are not so perfect are put in
another grade and sell for prices that vary according to the demand.
Eggs, of course, differ in appearance and in many cases they are sorted
in order to satisfy the demand. For instance, in some localities, eggs
having a brown shell sell for the highest price, while in other places,
eggs having a white shell are in the greatest demand and bring the
highest price. Unsorted eggs are not held in much favor and do not
bring so good a price as those which are all one color. Many persons
have an idea that the color of the shell of an egg bears some relation
to its nutritive value and flavor. However, authorities on foods agree
that, other things being alike, the edible portion of white-shelled eggs
has essentially the same composition and nutritive value as that of
dark-shelled eggs.
15. QUALITY OF EGGS.--The natural quality of eggs depends largely on the
food of the hens and their conditions of living. Because of this fact,
the selection, breeding, and care of fowls have developed into a
science, particularly since the production of eggs has grown into an
industry. When the quality itself is to be determined, all the
characteristics of eggs must be taken into consideration; still there is
one particular point on which the quality of eggs depends, and that is
their freshness. Various agencies, however, are constantly at work to
render this quality inferior. Chief among these are the molds and
bacteria that pass through the porous shells of eggs that have been
improperly cared for or have become contaminated by being allowed to
remain in unclean surroundings. Such bacteria are responsible for the
unpleasant flavors that are found in bad eggs. Because of their harmful
effect, every effort should be made to prevent the entrance of the germs
that cause decay, and, as has been stated, the best way in which to
accomplish this is to protect the shell. If it is found that bacteria
have entered, the eggs will become unfit for use quickly unless their
growth is prevented. This may be done by storing the eggs at a
temperature that will keep the bacteria dormant, or inert.
16. If the eggs are kept under the proper conditions, they will not
actually spoil for a long time; but it is seldom that they are not more
or less affected by storage of any kind that covers a period of several
months. One change that can always be looked for in such eggs is in the
air space at the broad end. When an egg is first laid, this air space is
small, but since the water contained in the egg slowly evaporates
through the porous shell it increases in size as the egg grows staler.
For this reason, the freshness of an egg can often be determined by the
size of this air space.
In addition, the purposes for which eggs are used are somewhat affected
by their storage. A stale egg, although it may not be actually spoiled
to the extent that it cannot be used as food, will not produce such good
results in a cooking process as a fresh egg, especially if it is used
for leavening. In fact, it is impossible to produce the desired results
with eggs that have undergone a certain amount of change, even though
their odor and their flavor do not indicate that they are spoiled.
17. JUDGING THE QUALITY OF EGGS IN THE MARKET.--While, as has been
mentioned, the housewife must depend considerably on the dealer's word
as to the freshness of the eggs she purchases, it will be well for her
to be familiar with the trade names of eggs and their meaning. The names
used differ, of course, in various localities, but all large
distributors grade and name eggs in much the same way. In deciding on
the grade to which eggs belong, a certain number of points are given for
color, size, freshness, and appearance, and the sum total of these
points determines the grade, a special name being given for each grade.
For instance, eggs that can be graded 90 are called _extra fancy_; those
which receive a grade of 80, _fancy_; those which are graded 70,
_strictly fresh_; and those which can be graded only 60, _cooking eggs_.
When eggs are put on the market under such names, it can be expected
that the quality will correspond to the grade and the price will vary
with the grade. Therefore, the trade name and the price are two of the
principal ways in which the quality of eggs in the market may be judged.
18. Another way of judging the quality of eggs consists in observing the
condition of the surface of the shell. When eggs are freshly laid, the
shell is covered with a substance, called _bloom_, that gives it a
feeling much like that of a thin lime coating deposited in a pan after
water boils. This coating disappears gradually as the egg is exposed to
the air, but as long as it remains, the egg may be considered as fresh
and germ-proof. While this way of determining freshness is probably the
quickest, it is possible that the quality of some eggs from which the
bloom has recently disappeared has not been injured.
19. When eggs are selected in the market, certain points in their
appearance should also be noted. If eggs of the best quality are
desired, medium-sized ones that are uniform in size and color should be
selected. With regard to shape, they should have a comparatively long
oval shell, one end of which is blunt and the other, a sharp curve.
[Illustration: FIG. 2: Internal structure of egg.]
[Illustration: FIG. 3: FRESH, 3 WEEKS, 3 MONTHS, OLDER.]
20. JUDGING THE QUALITY OF EGGS IN THE HOME.--After eggs have been
received in the home, several simple tests for determining their
freshness can be applied in addition to the ones already mentioned. A
rather indefinite test, but one that is sometimes applied to determine
the freshness of an egg, is to shake it. However, to be able to carry
out this test successfully, it is well to understand the interior
structure of an egg. Fig. 2 illustrates this clearly. At _a_ is shown
the air space previously mentioned; at _b_, the spiral cords that run
from the yolk to each end of the egg and hold the yolk in place; at _c_,
the yolk; and at _d_, the white. When the water inside the shell
evaporates, the yolk and white shrink so much that they can be felt
moving from side to side when the egg is shaken. The staler the egg, the
more pronounced does the movement become. This method should be applied
only immediately before the egg is to be used, as the thin membrane
between the yolk and the white and the spiral cords that hold up the
yolk are liable to be disturbed by the shaking. If they are broken, the
yolk will settle and finally adhere to the shell in case the egg is
stored for any length of time after that.
[Illustration: FIG. 4: Testing the egg.]
[Illustration: FIG. 5: four eggs.]
21. If nothing has been done to preserve eggs, the simple test for
freshness illustrated in Fig. 3, which consists in placing the eggs in a
glass containing water, will be found effective. A perfectly fresh egg
will sink when it is put into the water, but if the egg is 3 weeks old
the broad end will rise slightly from the bottom of the glass. An egg
that is 3 months old will sink into water until only a slight portion of
the shell remains exposed; whereas, if the egg is older or stale, it
will rise in the water until nearly half of it is exposed. 22. The
test known as candling, which is usually applied to eggs before they are
put on the market, can also be practiced by the housewife in the home.
This method of determining the freshness of eggs consists in placing a
piece of cardboard containing a hole a little smaller than an egg
between the eye and a light, which may be from a lamp, a gas jet, or an
electric light, and holding the egg in front of the light in the manner
shown in Fig. 4. The rays of light passing through the egg show the
condition of the egg, the size of its air space, and the growth of mold
or the spoiling of the egg by any ordinary means.
[Illustration: FIG. 6 (_a_) (_b_)]
In Fig. 5 is shown how an egg at various stages of freshness appears
when candled. When an egg is fresh, it will appear as in (_a_); that is,
the yolk will be barely distinguishable from the white except as a
slightly darker area in the center of the egg, and the entire egg will
appear clear and bright and free from spots. In an egg that is a little
older, candling will reveal a slightly darker yolk, a cloudy white, and
a larger air space, as in (_b_). In a watery egg, or one that is
beginning to spoil, various dark spots and blotches usually develop, as
view (_c_) indicates. When an egg is rotten, the contents of the shell
will look dark in candling and the yolk will appear to be mixed with the
white, as in (_d_). 23. If the housewife does not wish to resort to
candling, she may determine the condition of an egg by breaking it into
a saucer and examining it carefully. If the egg is newly laid, no odor
will be detected and the white will be clear, elastic, and rather thick;
also, where it joins the yolk it will be almost solid. The yolk of such
an egg will have an even yellow color, without lighter or darker spots
and, as shown in Fig. 6 (_a_), will stand up well from the surface of
the white. Sometimes a small spot of blood may be detected on the yolk
of a perfectly fresh egg, but, while this is not pleasant to look at, it
does not affect the quality of the egg. When an egg that is not real
fresh is broken into a saucer, the yolk will lie flat, as in (_b_). In
an egg that is quite stale, the membrane surrounding the yolk is easily
destroyed, so that even when such an egg is broken carefully the yolk
and the white are likely to run together.
* * * * *