I made half od a batch of the Very Vanilla Swiss Meringue Buttercream and made it chocolate. My question is.... It whips up like Meringue until you add the butter in then it kinda deflates, then when I put the chocolate in and turned it up a little it seemed to kinda fluff back up, but still seems kinda runny. Will this thicken as it sits?
You can try chilling it a bit- and then rewhip, if needed.
To save soupy IMBC, it's recommended to just continue beating (using a cold water bath) until the mixture comes together.
Don't know if this helps or not.