Tofu is made by coagulating soy milk and pressing the resulting curds. Although pre-made soy milk may be used, some tofu producers begin by making their own soy milk, which is produced by soaking, grinding, boiling and straining dried (or, less commonly, fresh) soybeans.[citation needed]
Coagulation of the protein and oil (emulsion) suspended in the boiled soy milk is the most important step in the production of tofu. This process is accomplished with the aid of coagulants. Two types of coagulants (salts and acids) are used commercially.[17] The third type of coagulant, enzymes, is not yet used commercially but shows potential for producing both firm and "silken" tofu.[citation needed]