Egg White Icing Refrigeration

Hi, GilM, Congrats on making your first post. I look forward to many more to come!

No, the pasteurized whites aren't raw per se; they are heat-treated whites, and they are heat-treated to help kill off harmful bacteria. Of course, if you leave any moist object out on the counter for a period, it can grow mold. Or if you cross-contaminate it with something else not in the egg whites, you might get into trouble. But, if you do neither of those things, you are simply setting the icing out to dry, which it does quite quickly. As the icing dries, the conditions under which bacteria can grow are greatly diminished, especially if there was little to no bacteria in the eggs to begin with (and you didn't cross-contaminate).

Thank you for the reply!  That makes me feel better about working with it. 😀

What if regular egg whites were used? They don't say pasteurized.

Thank you

@Pam Block posted:

What if regular egg whites were used? They don't say pasteurized.

Thank you

My comment above holds. There is always some risk of salmonella with raw eggs, and that bacteria will  grow more quickly in foods left at room temperature. But if the eggs are not infected with THAT bacteria to start, then THAT bacteria won’t spontaneously arise in it. The icing will set very fast and minimize the risk of other bacterial growth. Always some risk, but the fact is the icing won’t dry or dry properly on cookies if they are refrigerated after icing them.

This was so helpful!  I have a related question.  I used pasteurized egg whites in my royal icing.  The icing was in the frig about 5 days before I iced this last batch of cookies.  I iced the cookies 1-2 days ago.   How long can my iced cookies safely sit in a container (zip lock bag or tupperware)? I was going to hand these out to friends today, but started worrying!  Thank you!

@Donna Coker posted:

This was so helpful!  I have a related question.  I used pasteurized egg whites in my royal icing.  The icing was in the frig about 5 days before I iced this last batch of cookies.  I iced the cookies 1-2 days ago.   How long can my iced cookies safely sit in a container (zip lock bag or tupperware)? I was going to hand these out to friends today, but started worrying!  Thank you!

Pasteurized whites are heat-treated to kill harmful bacteria like salmonella. So cookies iced with pasteurized white-icing can safely sit out almost indefinitely. The same would be true even if you made icing with regular eggs PROVIDED those eggs were salmonella- free to start. If the icing is bacteria-free to start, it's unlikely you'll cross-contaminate the icing if the cookies are sealed, and/or that any bacteria in the icing will grow (because the sugar content of the icing is so high, and that suppresses bacterial growth). The bigger question, which is independent of the icing, is how long the cookies will remain tasty before they go stale.