Cheesemaking is a complex science—a food chemist explains the process from milk to mozzarella

Cheese is a relatively simple food. It's made with milk, enzymes—these are proteins that can chop up other proteins—bacterial cultures and salt. Lots of complex chemistry goes into the cheesemaking process, which can determine whether the cheese turns out soft and gooey like mozzarella or hard and fragrant like Parmesan.