Swiss Meringue DISASTER!!!

It sounds like you may have tried to rewhip it before it came completely to room temperature.  In my experience, once it separates to butter chunks and clear syrup it is lost.  Sorry.  

I'm sorry you had that happen.    In future definitely let it come fully to room temp before you put it back into the mixer.  The other thing to remember is that you don't really have to refrigerate it if you've made it the day before.  It will be fine out on the counter until you need it.

I've done that before, I was completely gutted after finally getting it right the day before! 

I've never made Swiss meringue buttercream but I do make Italian meringue buttercream regularly, I understand it is similar.

This happened to me when the buttercream was too cold - I soaked a teatowel in the hottest water I could stand and wrung it out well then wrapped it around the mixer bowl and held it there whilst still whisking the separated buttercream - it eventually came together and was fine to use.  You may need to reheat the teatowel a few times to warm the mixture up sufficiently to recombine.

I don't know if this will be any help to you as you've already tried to reheat in the microwave but it might be worth a try before you bin the entire mixture, and might be useful for the future.
 

Strange that you couldn't pull it back.. if it looked dull and kind of "curdled", it's just too cold. I don't think you can turn it into something else like whipped cream. I've never waited for it to be room temperature before whipping. At school we usually dumped the solid chunk into the 60 qt mixer and heated the bowl with a blowtorch LOL!

Quote:

Originally Posted by planetsomsom 

Strange that you couldn't pull it back.. if it looked dull and kind of "curdled", it's just too cold. I don't think you can turn it into something else like whipped cream. I've never waited for it to be room temperature before whipping. At school we usually dumped the solid chunk into the 60 qt mixer and heated the bowl with a blowtorch LOL!

Yep, from freezer to mixer. Chef would go: "Cut it up with a knife, and use the beater, don't break my whisk!" Looked a mess for a while but that sucker always came back together. 

Quote:

Originally Posted by planetsomsom 

Strange that you couldn't pull it back.. if it looked dull and kind of "curdled", it's just too cold. I don't think you can turn it into something else like whipped cream. I've never waited for it to be room temperature before whipping. At school we usually dumped the solid chunk into the 60 qt mixer and heated the bowl with a blowtorch LOL!

Yeeeeep. I chunk it up, and sit it over the burner on my stove until a good amount is melted, then it gets mixed back to it's beautiful fluffy soft self!