Making Italian buttercream frosting--everything was going picture-perfectly until I started adding bits of chilled butter to the egg whites at high speed. Now it's runny like craft glue. What happened?
Hmmm... Did you beat the meringue until it was completely cool? Are you working in a hot kitchen? My suspicion is the mixture got too hot.
HLA, you're probably stronger here than I, but I think that your buttercream can probably be salvaged! It doesn't sound like it broke (though maybe it did) but here is a good run down of ways to fix a buttercream in crisis! http://www.thekitchn.com...
SUCCESS! Turns out the problem was me! I got spooked after adding just 1/2 of the butter. Decided to go out in a blaze of buttered glory and dumped the rest in, and when I did, it came together again. Happy endings all around. Thank you both!!