【How-to】Where to buy rennet - Howto.org

Milk for Mozzarella: Almost any milk can be used for making mozzarella: whole, 2%, skim, cow, goat, raw, organic, or pasteurized. Pasteurized milk is fine to use, but make sure that it is not ultra high temperature (UHT) pasteurized. The proteins in UHT milk have lost their ability to set into curds.