I've had this happen a couple of different times and I'm not sure what I'm doing wrong... I've mixed up two different batches of shortening based buttercream to use for piping and it keeps separating. I think it is from the heat of my hand, but I was told that if you use an all shortening (no butter) recipe, this shouldn't happen. Does this happen to anyone else and what can I do differently? Here is my recipe:

shortening based buttercream:

1 cup CK high-ratio shortening

1 lb sifted CS

1 Tbsp meringue powder

3-4 Tbsp water

1 tsp clear vanilla

I just cream the shortening in my KA mixer and add the other ingredients, then mix for a few minutes...

I have no idea if this would work for you but try adding a HEAPING tablespoon or two full of plain old white flour to the icing and instead of water, add milk.  The "add four" tip comes from the change in the Crisco shortening to all vegetable and high ratio is suppose to fix the weakness in the new Crisco.  But I haven't seen much of a change between the both so I add flour anyway and it really does make a difference.  Adding milk is advised to keep colored icings from separating - something about the fat in milk mixing in with the fat in the icing better than water - oil and water won't mix as well.  Hot hands usually results in melted icing but not in separating.  Hope this helps.

AInstead of water I use heavy whipping cream

I used to use milk, but I always get worried about the dairy not being refrigerated. I know about the high amount of sugar acting as a preservative thing...but I still worry.

I didn't see both replies somehow... Thank you both for your responses! I will try to add flour and I will give it a shot with milk again. The bit about the fat in the milk mixing better makes sense. Thanks agian!!!!!!