Every egg has three parts, the shell, the yolk and albumen.
The shell prevents microbes from entering and any moisture from escaping. It is also there to protect the egg when being handled and transported. The shell can vary in color due to the breed of the hen. The color; however, has no effect on the quality, flavor or nutrition.
The yolk is the yellow portion of the egg. It is generally just over one-third of the egg and makes up for three-quarters of the calories. Most the minerals, vitamins and fat come from the yolk. Lecithin is found in the yolk. This compound is responsible for the emulsification in products like sabayon sauce and French buttercream icing. The color of the yolk can vary depending on the feed of the hen, but it does not affect the quality or nutritional content. Egg yolks solidify (coagulate) at temperatures between 149-158° F (65-70° C).
The albumen is the clear portion of the egg, also known as the egg white. It makes up about two-thirds of the egg and contains more than half the egg's protein. Egg whites coagulate, become firm and turn white in temperatures of 144-149° F (62-65° C).
The Chalazae cords, a very misunderstood part of the egg are the twisted strands of egg white. They are there to anchor the yolk in place. They are not imperfections or embryos. The more prominent they are, the fresher the egg.
Eggs come in different sizes. When reading a recipe and it does not specify size, you should always assume that the eggs are to be large. Sizes of eggs are jumbo, extra-large, large, medium, small and pee wee. They sizes are determined by weight per dozen. For example, a dozen large eggs should be 24 ounces. The other sizes are plus or minus 3 ounces per dozen.
**The average weight of a large egg once shelled is 1.6 ounces (50 grams). The egg white is 1 ounce (30 grams) and the yolk 0.6 ounce (20 grams).
Did you know, that eggs stored one day at room temperature age more than one week stored under proper refrigeration?
Eggs should be stored in temperatures below 45° F (7° C) and a relative humidity of 70-80 percent.
Understanding Egg Grades
|GRADE AA||GRADE A||GRADE B|
|SPREAD*||Remains compact||Spreads slightly||Spreads over a wide area|
|Albumen||Clear, thick and firm; prominent chalazae||Clear and reasonably firm, prominent chalazae||Clear; weak or watery|
|Yolk||Firm, centered, stands round and high, free from defects||Firm, stands fairly high, practically-free from defects||Enlarged and flattened, may show slight defects|
|Shell||Clean, of normal shape, unbroken||-||May show slight stains, permissible; abnormal shape, unbroken|
|Ideal Use||Any use, particularly frying, poaching and cooking in shell||-||Baking, scrambling, used in bulk-egg products|