Which method of preparing meringue helps improve its stability?

The method of slightly heating egg whites before beating them is known to enhance the stability of meringue. When egg whites are heated to a certain temperature (typically around 110°F or 43°C), the proteins begin to denature, which means they unravel and can then form a stronger network when whipped. This process allows the formation of a more stable foam, which holds air better and results in a firmer meringue.

In the context of meringue, stability is crucial, particularly for applications such as pavlovas or meringue pies, where structural integrity is needed to maintain shape and texture after baking. This method also helps to dissolve sugar more effectively, leading to a smoother meringue.

Other methods, such as beating at room temperature or starting to beat slowly, do contribute to the whipping process, but they do not have the same effect on the protein structure as heating. Similarly, using cold egg whites could lead to less stable meringue because the proteins are not as easily activated or able to incorporate air efficiently, resulting in a weaker foam.