Calcium Sulfate
The short version
Food-grade gypsum — a firming agent and the classic coagulant that sets soy milk into tofu.
It's widely considered safe at the amounts used in food, so we mark it green. The Safety section below has the details.
Where it comes from
The mineral gypsum (or anhydrite). Partially dehydrated, it is 'plaster of Paris'.
How it's used
Firming agent, dough conditioner, and calcium source — and the classic coagulant that sets soy milk into tofu. Also a free-flow aid and a yeast nutrient in brewing and baking.
Safety profile
No ADI specified. Poorly soluble and largely unabsorbed; a useful calcium source.
Physical & chemical properties
White powder, slightly soluble in water; the hemihydrate ('plaster') sets hard when mixed with water.
Regulation worldwide
Permitted in the EU, the US (GRAS), and globally.
Educational information only. Not medical or dietary advice.