re: Swiss buttercream disaster

Swiss, put the buttercream back in your mixing bowl and on low to medium low beat it with the paddle attachment not the wisk. It might take some time but should come back together perfectly.

Swiss meringue is always started with the whip attachment to make your meringue, but when you go to add butter, you always want to switch to your paddle attachment!

Good luck! Let me know if this helps you!