What to Know About Buying, Cooking and Eating Eggs
Sources: On Food and Cooking by Harold McGee; Food Lover's Companion by Sharon Tyler Herbst; The American Egg Board
How many calories in an egg?
A large egg has 75 calories and most are in the yolk. There are only 16 calories in the egg white, and no fat nor cholesterol. While the yolk has about 213 mg. of cholesterol, at the same time a whole egg is an excellent source of protein, riboflavin, iron and vitamins A and D and other nutrients.
What's the difference between a brown and a white egg?
Nothing except the color of the shell. And this is determined by the breed and diet of the hen that laid the egg. Sometimes, but not always, the color of the hen's feathers will foretell the color of the eggs and others say that it's revealed by the color of a chicken's ear lobe but who knew hens had ear lobes and how can we ever check such a thing? What's important to know is that the quality and flavor of an egg is best predicted by the quality of the farmer who is caring for the hens, not the color of the shell.
Should I always buy grade AA eggs?
Eggs are graded AA, A or B based upon the quality of the egg's interior and exterior when it left the farm. The grade doesn't have anything to do with freshness or size and grade A is commonly found in our markets. What matters more than grade is freshness so if you have a choice between a very fresh grade A and a less fresh grade AA, choose the fresher A.
What size eggs should I buy?
Recipe and nutrition protocol calls for large eggs. That means any recipe that says 1 egg is assuming that you're using a large one. The size is based upon the minimum weight per dozen: jumbo = 30 oz., extra large = 27 oz., large = 24 oz., medium = 21 oz., and small = 18 oz. If you're only buying eggs to scramble or fry and prefer a larger size, just remember that you're also increasing your caloric and cholesterol intake.
Tip: Many of NYC's greenmarkets and better butchers,sell eggs from area egg farmers including Knoll Krest Farm Fresh Eggs, Quattro's, and Tello's Green Farm Eggs. The difference in flavor between a local, organic or small farm egg and a supermarket one can be remarkable so it can be worth the challenge of transporting a carton home on the subway.
How should I store eggs?
Always refrigerate your eggs and keep them large-end up in their original store cartons instead of transferring them to those useless egg-holding trays in your refrigerator. Egg shells are porous so if you expose eggs to the air inside your refrigerator, they easily can absorb food odors.
How long do eggs keep?
Egg cartons from USDA-inspected farms must be dated on the day they're packed. Some will also have an expiration date. Raw eggs can usually be kept up to a month from the day they were packed, in the refrigerator. If you instead keep eggs at room temperature, know that they will lose more quality in one day than if stored in the refrigerator for a week. A hard-cooked egg can be kept in the refrigerator for up to one week. If you open a carton and any eggs are cracked, discard them because the protective shell has been violated and it could cause the egg to spoil.
Can I freeze eggs?
Egg whites freeze beautifully and can be kept frozen for up to 6 months. Just put them in a sealed plastic container. You can also use an ice cube tray to freeze individual eggs whites, transferring the individual "egg cubes" into a sealed plastic bag after they've frozen. Freezing egg yolks is another matter. You have to combine some sugar with the yolks and cover them with water and even then, they don't recover well when defrosted. Don't bother.
Why are some egg yolks a different shade of yellow than others?
The color of the yolk will depend upon the hen's diet. Wheat-fed hen's yolks will be a paler yellow than those fed a diet of alfalfa, grass or yellow corn.
If I see a spot of blood on a yolk, does this mean the egg is fertilized?
No. It's just a natural residue on the yolk that occurs when the egg is formed. Some say it's a sign of freshness because this kind of spot will fade as the egg ages. But if you have any question about the condition of an egg, discard it.
What about salmonella? Are raw eggs too risky to use in recipes like Caesar salads?
Salmonella is a bacteria that causes an illness that can be dangerous to the very young, the very old, and anyone with a compromised immune system. Today it is extremely rare (some say 1 in 20,000 eggs) but if you have concerns, especially if there has been a recent egg recall, you should partially or completely cook your eggs. To kill the bacteria, cook an egg to 140º F for 5 minutes (the yolk will stay runny) or to 160º F (the yolk will slightly harden) for 1 minute. The alternative is to purchase pasteurized eggs (they're more costly) which have been heated enough to kill the bacteria without cooking the eggs.
Also remember that eggs come from chicken farms, not exactly sanitary places. So handle eggs as you do raw chicken -- keep the eggs in their carton and separate from other food, discard any that are broken, and wash your hands after handling them.
Which came first, the chicken or the egg?
There are two theories. If you believe Genesis, it's the chicken because all the creatures (chickens, not eggs) were created at once so the egg followed. However, if you agree with American Indian lore, you believe that the Great Spirit came from a giant golden egg to create the world. So it would be the egg. It's up to you.