I've read a number of posts and blogs on BC icing that note it's best to use shortening that is not trans-fat free. The shortening in my grocery store is only trans-fat free and I'm wondering if this will cause any problems with the Buttercream recipes I'm considering. Do I need to compensate somehow? Thanks.

I recently switched to shortening with transfats in it.  It really does make a difference in my buttercream.  I thought that my buttercream was good before and I had finally gotten a recipe that smoothed fairly easy with a bench scraper.  I tried a couple of cakes with transfat shortening and my icing tasted better and was easier to get smooth.  I figure the extra cost is made up by saving me time.

I can't buy it at the grocery store either.  You might try asking another baker in your area or you can order it online. 

AIn California, the health department said you can't sell goods with trans fats. So all I can find is trans fat free shortening.

I worked with someone who would order trans fat shortening from out of state, and when the health department was scheduled to come in, they would hide the shortening or put it in different containers.

AThe main difference with trans-fat free shortening (e.g. Sweetex Z vs. Sweetex) is that the TF-free products turn out to be more temperature sensitive.