What do I do with leftover egg whites? How long are they safe for? I made two Leche Flan the night before last, each calling for 10 egg yolks...so, I was left with about 20 egg whites. I've stored them in the fridge in a tupperware container. How long are they good for? What can I make with them (other than scrambled egg whites and frosting)?
I can't really answer the question on what to do with the egg whites but the question how long the egg whites are good: two to four days.

Hmm, what about macaroons?