How to beat egg whites

Whisk at high speed.

You can add a teaspoon of lemon juice before you start beating to prevent them from "graining" (forming small grains), which can happen with very fresh egg whites.

If the egg whites are to be sweetened (for meringues, for example), add 2 tablespoons of the sugar halfway through the whipping, to support them and help them rise.

Beating egg whites incorporates air, which creates a foam made up of ever smaller bubbles of air and drops of white (albumen + water), see the microscope photo on right.

This fact give us some rules for egg whites:

• Fresh egg whites give better results that old ones, because they contain more water.
• If you add water or a liquid which contains some (fruit juice, ...) to egg whites to be beaten, you will have a greater volume of foam.
• Fat is the enemy when beating egg whites, because it obstructs or prevents the formation of foam, so it's necessary to be sure that the egg whites contain no traces of yolk (not a drop), and that the container that you're going to use is completely clean (be particularly careful with plastic bowls).