What Are Eggs and How Can I Use Them?

Egg whites are the clear part of the egg, called the albumen, that surrounds the yolk. About two-thirds of a large egg's shelled weight is white, and roughly 90% of that is water. The rest is mostly protein, with trace minerals and glucose and almost no fat.

That protein is the whole reason cooks separate whites out. When you beat them, the proteins unfold and trap air, building the foam behind meringue and angel food cake.

They also set firm and pale when heated, which is why a white-only scramble cooks up lighter than a whole egg.

For the eggs hub and the difference between whites and yolks, see /recipes/eggs.

The yolk is the rich, golden center of the egg. It carries almost everything that makes eggs valuable in the kitchen beyond plain protein: the fat, the fat-soluble vitamins (A, D, E, and K), and the natural emulsifier lecithin that lets oil and water bind into a smooth sauce.

A large yolk is about 33% of the egg's liquid weight and roughly 55 calories, most of it fat. That fat is the point: it is what gives custards their silk and rich doughs their tenderness.

For the basics of buying and storing eggs, see the eggs hub. This page is about what the yolk does on its own.

Liquid egg substitute is pourable egg sold in a carton, the kind branded as Egg Beaters. Despite the name it is mostly real egg: about 99% egg white, with the yolk removed and a little color and a stabilizing gum added back.

Pulling the yolk is the whole point. It strips out the cholesterol and most of the fat while keeping the protein, which is why it became a fixture of lighter breakfasts and low-cholesterol baking.

What you trade away is everything the yolk does: the richness, the golden color, the emulsifying power that holds custards and rich batters together.

A hard-boiled egg is simply a whole egg cooked in its shell until both the white and the yolk are fully firm. It is the backbone of deviled eggs, egg salad, and countless composed salads, and it travels well as a protein you can make ahead by the dozen.

The whole game is timing and cooling. Done right you get a tender white and a bright, creamy yolk; done wrong you get a rubbery white and a yolk ringed in gray-green.

For egg sizing and storage in general, see the eggs hub. This page is about getting the boil itself right.

Egg product is the catch-all term for processed, pasteurized egg sold out of the shell, in cartons or frozen tubs. It might be plain whole egg, or it might be a yolk-removed blend of mostly egg white, the same category grocery shoppers know best as liquid egg substitute.

The defining feature is pasteurization. The egg has been heated just enough to kill salmonella, which makes it safe in dishes where the egg stays raw or barely cooked and gives it a longer, more predictable shelf life than shell eggs.

For shell eggs and general egg handling, see the eggs hub.

Powdered egg substitute is a dry mix that stands in for eggs in baking, sold in a box or pouch and stirred together with water when you need it. Most of these are egg-free, built from starches like potato or tapioca, plus leavening.

That combination binds and lifts a batter without any egg at all. It is a go-to for vegans and for anyone with an egg allergy.

It is also handy when you simply have no eggs in the house, since the box sits in the pantry for months.

One thing to clear up: this is not the same as liquid egg substitute in a carton, which is real egg white with the yolk removed. Powdered replacers usually contain no egg. Check the label if egg allergy is the concern.

For everything about real eggs, see the /recipes/eggs hub.

An egg wash is a beaten egg, often loosened with a splash of water or milk, brushed onto dough before baking. It is not an ingredient you eat on its own so much as a finishing technique that controls how a crust looks and behaves in the oven.

The egg proteins brown and the sugars caramelize under heat, so a washed crust comes out glossy and deep golden where an unwashed one stays pale and matte. The same brush of egg also acts as glue.

For everything about eggs themselves, see the eggs hub. This page is about the wash and how to use it.

Quail eggs are the tiny, speckled eggs of the quail, about the size of a large olive and weighing roughly 9 grams each. Their shells are cream-colored with brown blotches, and the membrane underneath is surprisingly tough for something so small.

By volume it takes about 5 quail eggs to equal one large chicken egg. That is the number to remember when you want to swap them into a recipe.

The flavor is close to a chicken egg but a touch richer, since the yolk makes up a larger share of the whole. For general egg handling, see the eggs hub. This page covers what is different about cooking the small ones.

Dried eggs are whole eggs, white and yolk together, pasteurized and dehydrated into a pale yellow powder. Add water back and you have something close to a beaten whole egg, ready to scramble or stir into batter.

Unlike powdered white, this is the full egg, so it carries the yolk's fat and color and rich flavor. That makes it a real one-for-one stand-in for fresh eggs in cooking and baking, not just a foaming agent.

The draw is shelf life and convenience. A sealed can keeps for years without refrigeration, which is why dried eggs are a staple for camping, backpacking, emergency stores, and military rations.

For everything about fresh eggs, see the /recipes/eggs hub.