If you have difficulty in beating egg whites into stiff peaks, these ideas may be helpful to you.
The whites will separate from the yolk best when they are cold, but will triple in volume if they are beaten at room temperature. So after separating the eggs, let the whites rest for about 30 minutes to warm up. If you are in a hurry, the bowl of whites may be set into a larger container with very warm (not hot) water for about 10 minutes.
What you beat them in will make a big difference. A copper bowl is the best, because it makes high stiff peaks, takes less time to beat the whites and they will stay stiff longer. To get a similar result, the next best bowl would be stainless steel or glass. When beating them in an aluminum bowl they often turn a grayish color and look very unappetizing. Depending on what they have been used for, wooden bowls can have oil residue left from previous uses, and it can keep the whites from beating into stiff peaks.
Start beating the egg whites at low speed, gradually increasing the speed to medium-high. If you start at high speed it will cause air bubbles that keep the whites from making stiff peaks. Continue beating the whites and once they have reached the soft peak stage, gradually add the sugar (this ensures that the sugar fully dissolves into the foam). If sugar is added in the beginning it will take a lot of beating to get any peaks at all. Add the sugar a small amount at a time while you continue to beat. It helps to get stiff peaks and keep them from deflating if you add one-eighth teaspoon cream of tartar, lemon juice or vinegar for each egg white, or if you are making a meringue use one-eighth teaspoon for every two whites. Add before they begin to thicken.To make sure the sugar is completely added in, rub a little of the beaten white between your fingers. If it feels gritty, it needs to be beaten some more.
Be sure not to over beat, because the peaks will flatten and start to get watery. After you are finished beating, use them right away or the same thing will happen. If whites are over beaten they are apt to dry out.
If you are using the beaten whites as a meringue, you’ll have better success if you don’t make it in rainy or exceptionally humid weather. The meringue is mostly air, and moisture will make it go flat. To keep the meringue from shrinking, spread it on a pie when it’s hot.