Except where explicitly noted, recipes here (and most US cookbooks) are for large eggs. This is equivalent to a European medium egg, extra large in Australia, or large in New Zealand. If you're stuck with other sizes:
Blind tests have shown no difference in taste between mass produced or other types of egg. Other considerations (e.g. living conditions for the animals) are more of a factor in deciding egg types.
I prefer cage free eggs fed a vegetarian diet, free of antibiotics.
White = 90% water, 10% protein
Yolk = 50% water, 20% protein, 30% fat
http://en.wikipedia.org/wiki/Egg_(food)
http://en.wikipedia.org/wiki/Chicken_egg_sizes
Eggs: Some refrigerators urge you to put your eggs on the inside of their door. Don’t give in -- the door is the warmest part of the refrigerator. Eggs are happiest in their cartons on a shelf. Don't try to be European and store your eggs outside the refrigerator; eggs in the United States, unlike in Europe, are washed before sale so they lose their protective outer layer.
Fine Cooking:
Eggs are such as basic, everyday ingredient that it's easy to overlook their powerful and diverse functions in cooking and baking. Eggs give structure to baked goods (cakes, muffins, pancakes) as well as savory foods like meatloaf. They work as a leavener, thickener and binder in sauces like hollandaise and mayonnaise, and they give smoothness to everything from custards to truffles. On top of all their undercover work, eggs are nutritious and delicious on their own, whether poached, fried, scrambled, or made into an omelet or frittata. See egg yolks andegg whites for their specific uses, as well as prepping techniques.
kitchen math:
Eggs are sold in standard sizes: medium, large, extra-large, and jumbo. Most recipes call for large eggs; if a recipe doesn't specify, assume it means large.
1 large egg = 2 oz. = 3-1/4 Tbs. (1 Tbs. yolk; 2-1/4 Tbs. white)
1 extra-large egg = 4 Tbs.
1 medium egg = 3 Tbs.
5 whole large eggs = about 1 cup
don't have it?
In recipes that don't call for a lot of eggs, substituting one size for another is usually not a problem. However, as the number of eggs called for increases, the difference in amount will become more pronounced. When substituting a different-size egg, use the equivalents above to figure out the total volume you'd get from large eggs, then use however many eggs you need to reach that volume.
how to choose:
The most common eggs used in cooking are unfertilized hen eggs. Eggs can be brown or white (or even shades of pale greens and blue), which is determined by breed. Fresh eggs are your best bet for flavor, and farm-fresh are a great treat. At the supermarket, check the carton for a date. Though salmonella is rare in eggs, people at risk should not consume raw or undercooked eggs. Pasteurized eggs, available at many markets, are a good alternative in such cases.
how to prep:
Many recipes call for room-temperature eggs. To warm cold eggs quickly, put them in a bowl of warm water.
how to store:
Store eggs in the refrigerator in the carton in which they came. They'll keep for several weeks, though they're best used within one week.
Eggs are classified by size all over the world. The standard size of a chicken egg in the US is “large” and refers to an egg that is about 60 grams (from 57 to 64g, actually). Anything outside this range gets a different size designation: small, medium, extra large, jumbo. Since most commercially produced eggs fall into the large category, every recipe written in the US for US cooks assumes these as the standard size unless otherwise indicated in the recipe.
A large egg, cracked, yields approximately 3 1/2 tablespoons of liquid. The yolk will be about 1 1/2 tbsp and the whites will be about 2 tbsp. An extra large egg will have about 4 tbsp of liquid inside, while a medium egg will have only 3 tbsp. These differences have no effect whatsoever on omelettes, hard boiled eggs or many other savory dishes, but they can actually have a big impact on baked goods.
With a recipe that calls for only one egg, the difference between sizes may not be noticeable. Substituting 4 extra large eggs in a recipe that only calls for 4 large eggs will add an extra half-an-egg in volume to your recipe. This changes the ratios given in the recipe and can mean that you’ll end up with a drier or eggier finished product, one not quite as good as would have been achieved with the right sized eggs. Extra large eggs can be a good deal when it comes to eggs for breakfast, but if you know you’re going to be dealing with a lot of eggs for baking (especially in egg-heavy recipes), it is often best just to buy the size of egg dictated in the recipe itself (large, if not directly specified).
The size classifications vary a bit by country. In the UK, a large egg is slightly bigger than in the US. In Australia, it is slightly smaller. Keep in mind that these differences will not affect most recipes, but that when you are dealing with a large number of eggs it could become an issue and measuring or weighing your eggs is a good idea.
Do Cold Eggs Ruin Baked Goods? (America's Test Kitchen)
Cake recipes often call for room-temperature eggs, which incorporate into the batter more readily than cold eggs. We wondered, though, if the difference between room-temperature and cold eggs was so great that it could actually ruin a basic cake recipe.
THE EXPERIMENT
We conducted a blind tasting of two yellow cakes: one made with room-temperature eggs, the other with eggs pulled straight from the refrigerator. The cake prepared with cold eggs produced a slightly thicker batter and took five minutes longer to bake.
THE RESULTS
The cake made with room-temperature eggs had a slightly finer, more even crumb, but the cold-egg cake was entirely acceptable. Overall, tasters strained to detect differences between the two cakes, so it’s fine to use cold eggs in most basic cake recipes.
HOWEVER…
Cold eggs can cause problems in finicky cakes—such as pound, angel food, and chiffon—that rely on air incorporated into the beaten eggs as a primary means of leavening. In these cases, we found that cold eggs didn’t whip nearly as well as room-temperature eggs and the cakes didn’t rise properly. As a result, these cakes were too dense when made with cold eggs.
Here’s our tip: To quickly warm whole cold eggs to room temperature, place them in a bowl and cover them with hot—but not boiling—tap water for five minutes. Since it is easier to separate eggs when they are cold, eggs can be separated first and allowed to warm up while the remaining ingredients are assembled. If necessary, the whites or yolks can be placed in a bowl nestled within another bowl filled with warm water to speed up the process.