Powdered egg whites are egg whites that have had the liquid removed from them, and are thus easy to store, and great for any situation where you can’t transport fresh eggs. They’re usually reconstituted with a bit of water, and make for a great food for campers or backpackers, since they can be carried with ease, and then used for cooking when needed. Many, but not all, varieties of dried egg whites are pasteurized, which means they don’t have the same concerns of possible salmonella infection as do fresh eggs. This makes them excellent for recipes that call for the use of raw eggs.