Meringue, a light, airy mixture of stiffly beaten egg whites and sugar, adds a delicate touch to a wide variety of confections. Adding cream of tartar enhances the egg whites' volume.
The first written reference to meringue, called "white bisket bread," appeared in the handwritten cookbook of the English Lady Elinor Fettiplace, dated 1604.
The hardness or softness of meringue depends on how much sugar is beaten into the egg whites. Soft meringue is used in baked Alaska desserts, and as a topping for pies. While shells and cookies often require hard meringue.
How It Forms
Beating egg whites causes the protein to form a film that traps air bubbles and sugar stiffens the foam. The longer the meringue is beaten, the more the volume increases, according to the Baking 911 website.
The American Egg Board recommends that a 3 egg white soft meringue spread on hot, cooked pie filling be baked at 350 degrees F until the meringue reaches 160 degrees F (about 15 minutes). By cooking meringue properly you avoid any possibility of bacteria contamination.
Ensure the bowl you use to beat the egg whites remains spotlessly clean and grease-free, because even a small amount of grease or egg yolk can cause the meringue to collapse.