How to Separate Egg Whites from Yolks and Whip Them to Stiff Peaks

The cleanest way to separate an egg white from its yolk is to crack the egg on a flat surface, split the shell into two halves, and transfer the yolk from one half to the other while allowing the white to fall through your fingers or into a bowl. To whip egg whites to stiff peaks, the bowl and whisk must be completely free of fat. Even a trace of oil can keep the whites from increasing in volume.

How can you separate the white cleanly from the yolk?

Passing the yolk between the shell halves is a classic method, but the sharp shell edges can easily pierce the yolk membrane. Cracking the egg into a clean bowl and separating the yolk by hand or with a funnel may give a more reliable result. If the yolk membrane tears and yolk mixes into the white, the white may have difficulty reaching stiff peaks. When separating multiple eggs, crack each one into a separate bowl before transferring the white to the main bowl so a problem with one egg does not affect the others. A cold egg holds its yolk together more firmly than a room-temperature egg, so the yolk is less likely to break.

Why are egg whites so sensitive to fat?

As egg whites are whipped, their proteins form a thin network around air bubbles. Fat molecules interfere with the formation of this network and prevent the proteins from bonding properly. Plastic bowls can retain an invisible film of fat on their surface, so glass or metal bowls are more reliable than plastic for whipping egg whites. Wiping the bowl and whisk with a few drops of lemon juice or vinegar can help neutralize traces of fat and make whipping easier.

What steps should you follow to reach stiff peaks?

Begin whipping the egg whites at low speed. Gradually increase the speed once they begin to foam and gain volume. Starting at high speed can produce uneven, fragile bubbles. If adding sugar, add it gradually after the whites begin to foam rather than all at once. Sugar added too early can delay the whites from reaching their full volume. Egg whites have reached stiff peaks when a point stands straight up after you lift the whisk. If the point immediately leans over, continue whipping for a few more minutes.

Can over-whipped egg whites be saved?

Over-whipped egg whites lose their smooth shine and become clumpy and dull. They cannot be fully restored, but adding one more raw egg white and whisking gently may improve them somewhat. Under-whipped egg whites are still runny and will not hold their shape; in that case, continue whipping patiently.

A room-temperature bowl helps egg whites reach a higher volume faster than a cold bowl taken straight from the refrigerator, so the bowl's temperature can affect whipping time as well as the eggs' temperature. However, cold eggs are easier to separate. A practical sequence is to separate the eggs as soon as they come out of the refrigerator, then let the whites come to room temperature for about half an hour before whipping.