Whipping Egg whites

1. Egg whites are easier to separate when the eggs are cold.
2.  Wipe down your mixing bowl & beater with white vinegar to ensure that they are free of any lingering traces of oil or grease that could prevent egg whites from whipping up properly. The acid in the vinegar also negates the need for cream of tarter, so if your recipe calls for it, you can leave it.
3. Avoid using aluminum bowls & tools because any acid you add to whites to increase the stability will react with aluminum & turns egg whites gray. Never use cold bowls, as chilled egg whites will take longer time to reach full volume.
4. Egg whites expand up to 8 time in volume, So a mixing bowl accordingly.
5. Egg whites can be beaten to 3 stages. First level is Soft peak. It barley holds the shape. The peak flop over immediately when the beaters are lifted. Second stage is Medium peak. At this stage the whites holds their shape well, but the tip of the peak curls over itself when the beaters are lifted. Third stage is stiff peak. As the name says the peak stands straight.

6. Over beating the whites beyond the third stage results in dry & stiff whipped eggs, which will certainly collapse when heat is applied.
7. When the recipe calls for folding other ingredients after whipping, it is better to fold them using a wire  whisk than using a plastic or metal spatula.  Spatula will put weight on the whipped whites, making them to loose their volume.