The buttercream recipe I always follow says that I need to add flavor extract right after creaming shortening and butter, but this time I am making three different cakes with three different buttercream flavors. It's maybe a silly question, but it would be ok if I make all butter cream together and I add flavor exctacts at the end, I mean, after I divide the three portions of buttercream needed for each cake?
No problem. I do it all the time with SMBC, IMBC and ABC (which I use less commonly). I routinely make big batches of buttercream and divide it into separate batches for flavoring right away, (adjusting the flavoring amounts of course) and freeze extra unflavored in quart containers to use later as needed. When needed I bring the frozen BC to room temperature, rebeat it, and add flavorings, curds, chocolate, liqueurs, etc just as you would right off the bat.
Thank you for your answer! ;)