EGGS

EGGS

Eggs should be well understood by the baker because they are used in
large quantities in the bakeshop and are more expensive than many of
the other high-volume ingredients, such as flour and sugar. For
example, half or more of the ingredient cost of the average cake
batter is for the eggs.

COMPOSITION
A whole egg consists primarily of a yolk, a white, and a shell. In
addition, it contains a membrane that lines the shell and forms an air
cell at the large end, and two white strands called chalazae that hold the yolk
centered.
• The yolk is high in both fat and protein, and it contains iron and several
vitamins. Its color ranges from light to dark yellow, depending on the diet
of the chicken.
• The white is primarily albumin protein, which is clear and soluble when
raw but white and firm when coagulated.The white also contains sulfur.
• The shell is not the perfect package, in spite of what you may have heard. It
is not only fragile but also porous,allowing odors and flavors to be absorbed
by the egg and allowing the egg to lose moisture even if unbroken.
The table below lists the water, protein, and fat content of whole eggs,
whites, and yolks.

Average Composition of
Fresh Liquid Eggs
Whole eggs (%) Whites (%) Yolks (%)
Water 73 86 49
Protein 13 12 17
Fat 12 — 32
Minerals and 2 2 2
other components
The parts of an egg. The diagram shows, in
simplified form, the location of the parts of
an unbroken egg, as described in the text.

GRADES AND QUALITY
Grades
In the United States, eggs are graded for quality by the USDA.There are three
grades:AA,A, and B.The best grade (AA) has a firm white and yolk that stand
up high when broken onto a flat surface and do not spread over a large area.
As eggs age, they become thinner and are graded lower.The figure on page 48
shows the differences among grades AA, A, and B.
In Canada, there are four egg grades:A, B, C, and Canada Nest Run.
As a baker, you will not be concerned so much with the firmness of yolks
and whites. Rather, you will want eggs that are clean and fresh-tasting, free of
bad odors and tastes caused by spoilage or absorption of foreign odors. One
bad-smelling egg can ruin an entire batch of cakes.

Maintaining Quality
Proper storage is essential for maintaining quality. Eggs keep for weeks if held
at 36°F (2°C) but lose quality quickly if held at room temperature. In fact, they
can lose a full grade in one day at warm bakeshop temperatures.There’s no
point in paying for Grade AA eggs if they are Grade B by the time you use them.
Store eggs away from other foods that might pass on undesirable flavors or odors.

Size
Eggs are also graded by size.The table below gives the minimum weight per
dozen (including shell) of each size category. Note that each size differs from
the next by 3 oz per dozen. European eggs are also graded by size, with size 1
being the largest (70 g each, or about 2.5 oz) and 7 being the smallest
(45 g each, or about 1.6 oz).This weight includes the shell.
Large eggs are the standard size used in baking and in food service.Shelled
large whole eggs, yolks, and whites have the following approximate weights.
Average Large Eggs, Approximate Weights Without Shell
One whole egg = 1.67 oz 47 g
One egg white = 1 oz 28 g
One yolk = 0.67 oz 19 g
91⁄2 whole eggs = 1 lb 21 whole eggs = 1 kg
16 whites = 1 lb 36 whites = 1 kg
24 yolks = 1 lb 53 yolks = 1 kg
48 Chapter 3 • Ingredients
Egg Size Classifications
Minimum Weight per Dozen
Size U.S. Metric
Jumbo 30 oz 850 g
Extra large 27 oz 765 g
Large 24 oz 680 g
Medium 21 oz 595 g
Small 18 oz 510 g
Peewee 15 oz 425 g

Egg grades (a) Grade AA, (b) Grade A, and
(c) Grade B eggs, as seen from the top and
side. Note how the white and yolk lose
thickness and spread more in the lower
grades. Courtesy of USDA
a. b. c.
To measure small quantities or odd quantities of whole egg, such as 0.5 oz
or 15 g, beat the whole egg or eggs and then measure by weight.

MARKET FORMS
1. Fresh eggs or shell eggs

2. Frozen eggs Frozen eggs are usually made from high-quality fresh eggs
and are excellent for use in baking.They are pasteurized and are usually
purchased in 30-lb tins.
To thaw, place them unopened in refrigerator and hold for two days, or
place in a defrosting tank containing running water at 50° to 60°F (10° to
15°C) for about 6 hours. Do not defrost at room temperature or in warm
water. Stir well before using.
Whole eggs
Whole eggs with extra yolks
Whites
Yolks
Frozen yolks may contain a small amount of sugar (usually about 10%;
check the label) to keep the components from separating while frozen.
When sugared yolks are used in products such as cakes, you should allow
for their sugar content by reducing the sugar in the formula by the same
amount. For example, if you are using 20 oz yolks with 10% sugar, subtract
2 oz (20 oz × .10) from the sugar in the formula.

3. Dried eggs
Whole
Yolks
Whites
Dried eggs are sometimes used in the bakeshop, though less often than
frozen eggs. The whites are frequently used for making meringue
powders. Dried egg products are also used by commercial manufacturers
of cake mixes.
Dried eggs are incorporated in baked goods in two ways:by reconstituting
them with water to make liquid eggs, or by mixing them with the dry
ingredients and adding the extra water to the liquid portion of the formula.
It is important to follow manufacturers’ instructions for the ratio of egg
to water because egg products vary. After mixing, let the eggs stand to
allow time for the water to be absorbed.This takes 1 hour for whole eggs
and yolks, and sometimes 3 hours or more for whites. Mix again before
using.
The following are typical ratios for reconstituting eggs:
Product Ratio of egg to water by weight
Whole eggs 1:2.5
Yolks 1:1 to 1:1.5
Whites 1: 5.5 to 1: 6
Unlike most dried products,dried eggs do not keep well.Keep refrigerated
or frozen, tightly sealed.

SANITATION
In recent years,cases of salmonella food poisoning have been caused by raw or
undercooked eggs. As a result,cooks have been made more aware of sanitation
concerns with respect to eggs. Pasteurized egg products are used in more
operations. For a more detailed discussion of eggs and food safety.

FUNCTIONS
Eggs perform the following functions in baking:
1. Structure Like gluten protein, egg protein coagulates to give structure
to baked products. This is especially important in high-ratio cakes, in
which the high content of sugar and fat weakens the gluten.
If used in large quantities, eggs make baked products more tough or
chewy unless balanced by fat and sugar, which are tenderizers.
2. Emulsifying of fats and liquids Egg yolks contain natural emulsifiers
that help produce smooth batters.This action contributes to volume and
to texture.
3. Leavening Beaten eggs incorporate air in tiny cells or bubbles. In a
batter, this trapped air expands when heated and aids in leavening.
4. Shortening action The fat in egg yolks acts as a shortening.This is an
important function in products that are low in other fats.
5. Moisture Eggs are mostly water.This moisture
must be calculated as part of the total liquid in a formula. If yolks are
substituted for whole eggs, for example, or if dried eggs are used, adjust
the liquid in the formula to allow for the different moisture content of
these products.
6. Flavor
7. Nutritional value
8. Color Yolks impart a yellow color to doughs and batters. Also, eggs
brown easily and contribute to crust color.