I am making a dessert that needs egg whites beaten till fluffy. When I was separating the eggs one broke and now they are not beating up. Can I use

Store-bought egg whites are terrific. They are typically sold frozen, so set the container in a bowl of cold water to thaw. I know, it sounds counter-intuitive, but it is not only the safest means of thawing, but also the quickest.

Any yoke in there at all, and you have nothing but scrambled eggs, sadly. The fat from the yolk makes it impossible to use the whites as "egg white".

But egg whites are egg whites, so why would store bought egg whites not work ?

But let us know.