Asked in Meringue
Why it is important to use a particularly clean bowl when whisking egg whites to make a meringue?
Any bowl or utensil that is used when beating egg whites has to be perfectly clean and grease-free. When air is beaten into egg whites, the proteins of the egg white open up, which makes the whites form a semi-solid. If there are any lipids introduced into the egg whites they prevent the whites from forming a semi-solid state by surrounding the proteins of the egg whites and preventing the proteins from opening.