Hi all.
I have a question for you: Have you ever had white spots form on stored colored buttercream? I use all shortening, meringue powder, and a pinch of salt (among other ingredients). I wonder if it's a reaction from the meringue powder and/or salt. The spots almost look like mold, but they are defintely not. Once I stir the buttercream, they disappear; and they never form on an iced cake. I'd love to know if anyone has had this happen and if anyone knows WHY this happens. Thanks!

Hey Cookieman...can't say that I've ever had that happen but want to ask...how long has is been stored? I'ved stored mine for a couple of weeks and still have had no problems. Are they wet spots, or lumpy spots? Just trying to get a visual! Missey BTW...I saw you Valentine cookies on another site..........they look great!!

I made the buttercream today...and they appeared within hours! No, they are not lumpy at all. They just look like random "bleached" spots. Like I said, they disappear once you remix the buttercream and they do not affect the taste.
Thanks for the compliments!

My uneducated guess would be the salt. But I can't say that for sure.

I agree with Dawn, it is the salt, In some areas, the salt has a chemical reaction with your local water and brings out minerals in the water. So you are best off not using salt.
Hugs Squirrelly Cakes

Thanks Dawn and Squirrelly. I pretty much assumed that's what it was, but wanted some reassurance from the pros! I'm making another batch of buttercream this weekend and will leave out the salt. I'll report my findings soon thereafter.
Thanks again to everyone!

If you still need the salt for flavor, can you try salted butter instead of unsalted? The salt in the butter may not react as this added salt did.