I have made a lot of soap batches and had no problem unmolding the soaps. This time, I used a lard recipe with 5% superfat along with other oils (coconut and palm and castor) and after two days and putting the molds in the freezer I cannot unmold them from plastic molds without cracking the molds and messing up the shape of the soaps. Any ideas on why the soaps won't pop out of the molds? I sprayed with alcohol before pouring.