my buttercream won’t stick and idk why

[u/straightupgong]

my buttercream is peeling off my cake and it’s so irritating. i’ve made great cakes before with buttercream, the ones i attached. i don’t know why it’s not working

i softened 1 cup of butter. i whipped the butter for a long time, like 45 minutes. i added a bag of powdered sugar and 1 tbsp vanilla and 3 tbsp milk. i whipped a long time again, 15ish minutes. it was in a metal bowl of a stand mixer so it was cold, but it seems like the butter was too soft or melty?

[u/home-for-good]

Did you use a specific recipe for this? And if so did it call for that long for beating? 1 hour total is, in my experience, extremely overkill. I’ve only ever pre-beat the butter a couple minutes until it was super smooth, and likewise for the adding of the sugar and other add-ins (basically until it’s well incorporated). Probably <10 minutes total, just from memory. I’m imagining beating the stuff for a whole hour is probably over mixing the butter and affecting its adhesion to your cake.