Learning to whip egg whites is a right of passage for most cooks. It seems simple, just whip away until they get light and fluffy, right? Well, sort of. Not using the right equipment, eggs, or even doing things in the wrong order can all effect the volume and texture of your egg white foam. But, with a little science and these tips anyone can perfectly whip egg whites into a white, fluffy, dream-like foam.
Before you reach for the eggs, make sure you have the right equipment. Egg whites need to be whipped in glass, metal, or glazed ceramic bowls because plastic bowls have a thin, oily residue that can inhibit the egg whites from whipping. For the same reason, make sure your whisk or beaters are completely clean and dry.
Fresh eggs will achieve the fullest volume as they are slightly acidic and this helps stabilize the proteins. As an egg ages it slowly becomes more alkaline, which makes the proteins less stable. Room temperature eggs will whip easier, although cold eggs are easier to separate from the yolks. So, separate your eggs while they are still cold and then allow the whites to come to room temperature before whipping. If there is any amount of yolk in the whites, they will not whip.
The Whipping Process
Begin whipping your egg whites on low speed until they become foamy and frothy. Once the egg whites are foamy, increase the speed to high until they become whipped to the desired stage.
Stages of Whipped Egg Whites
Foamy - The egg whites are still primarily liquid, with some bubbles that may cause the egg whites to look slightly opaque.
Soft Peaks - The egg whites are now white, will hold their shape in the bowl, and will not slide out if the bowl is tipped sideways. When the beaters or whisk is lifted out of the egg whites, they will form soft peaks that slump over to the side.
Firm Peaks - When the beaters or whisk is lifted out of the egg whites, the peak will stand erect and not bend over. When firm peaks form, the egg white have reached their fullest volume and should not be beaten any longer.
Over Beaten Egg Whites - If egg whites are beaten past the point of stiff peaks, the matrix of proteins will begin to break down and the foam will collapse. The egg whites will become grainy, watery, and flat. Once the egg whites are over beaten, they can not be salvaged.
Other ingredients are often added to egg beaten egg whites either to add flavor to or to help the stability and increase volume. A pinch of salt or cream of tartar added to egg whites prior to beating will help stabilize the protein matrix and increase the volume. This is especially helpful with older eggs, which may have become slightly alkaline.
Sugar is often added to egg whites when making meringues and other desserts, but it is important to add the sugar correctly to preserve the integrity of the foam. Sugar must be added gradually to prevent collapsing the foam, so begin with a small amount once the egg whites are foamy, and continue to add it gradually as you beat. The sugar will cause the egg whites to take on a glossy appearance.
Using Whipped Egg Whites
Whipped egg whites should be used immediately as they may lose volume or weep moisture as they sit. Never beat or aggressively stir egg whites into other ingredients. Rather, other ingredients should be gently folded into the egg whites. Fold as few times as possible to combine the ingredients and maintain as much volume as possible.