I don't make many cakes, but when I do I like to use Sweetex for my icing. I got a 50-lb box and after about 2 months, I noticed it has little hard grains in it - they are still shortening, but they don't break up when I am mixing my icing. They stay as little whte dots when I color the icing and of course clog up my piping tips. My friend has had the same problem. I have been melting it down, putting it through a coffee filter and then letting it harden back up before using it, but that is a real pain. Has anyone else had this experience with Sweetex? Can anyone tell me what is happening and if there is a way to avoid it?

I don't know what it is, but at the price of that stuff, I'd be calling customer service to complain.