I was making a couple of batches of soap and, as usual, I planned to melt only my cocoa butter as I use the heat transfer method but don’t want to stir forever. I have always melted my cocoa butter in my Pyrex cups. And so, I measured out by 8 oz. of cocoa butter and popped it into my microwave for 2 minutes (not enough to totally melt it but enough to make it soft enough to melt completely more easily). Done. Poured the cocoa butter into one container and moved on to measure out the cocoa butter for my next batch. Measured the 8 oz. of cocoa butter into my container and picked up the Pyrex container and heard a crack. “Oh no! I think it’s going to break!” Yup - it did. I guess adding the cocoa butter to a too-hot Pyrex container was not smart. I will stick with my food-service containers from Webrestaurant Store. Photos attached - clean-up was a pain and I lost two large batches of soap to flying chards.