What coagulants are used for producing tofu?
Commonly used coagulants are Nigari (mostly Magnesium Chloride), Calcium Chloride, Calcium Sulfate, GDL (glucono-delta-lactone), citric acid, acetic acid (vinegar), etc. When using salts, ensure these are food grade. For Magnesium Chloride (MgCl2.6H2O) the toxic substance levels are required to be lower than the following (according to US-FDA): heavy metals, e.g. lead and mercury – 10 parts per million (ppm); arsenic – 3 ppm; and ammonium – 50 ppm. If in doubt when a coagulant is food grade or not, play safe by using readily available white vinegar or citric acid.
