Linked below is a custard/buttercream recipe posted by krissywatts awhile back. It's a great recipe, but what on earth did I do to it?
I made the frosting last night, following the instructions precisely. Then, I added half a teaspoon of Boyijian lemon oil, and the juice of half a lime. I think that's where I went wrong.
The frosting was light, fluffy, and smooth when I went to bed. I was sooo happy with it! This morning, it had set in the fridge, and still looked okay. But when it came back up to room temperature, it began to sweat a little (it's NOT hot in my apartment, 70 tops). I stirred it, and I could see that it had started to curdle ever so slightly. Since it wasn't too bad, I went ahead and frosted a cooled cake.
It looks gawdawful. The curdling is really obvious now that the frosting is spread on the cake, and ths frosting softened up really quickly and started sliding everywhere. I threw it back in the fridge, and now it's a little more stable but still ugly. Edible, but really really ugly.
Did the lime juice work its magic overnight? If it did, how do I go about making a lemon or limed flavored frosting?
Finally, a non-disaster related question for krissywatts: is this frosting supposed to set up hard enough to pipe, or do you think it's too soft for that?
Thanks to all for advice!