E509: Calcium chloride
What is E509?
Calcium chloride (E509) is a salt made of calcium and chlorine. It is a white, highly water-soluble solid that strongly attracts moisture and tastes salty with a slightly bitter edge.
Origin and production
It is obtained as a by-product of the Solvay process for making sodium carbonate, by reacting limestone with hydrochloric acid, or by refining natural brines.
Why is it used?
In cheesemaking it is added to milk to help rennet form a firm curd, which is why it is common in cheeses such as Gouda. It also keeps pickled cucumbers crisp and helps set tofu and some plant-based meat alternatives.
Vegan, vegetarian and halal
Calcium chloride is mineral in origin and suitable for vegans and vegetarians. Its use in cheese does not change whether the cheese itself is vegetarian, which depends on the type of rennet.
Safety and regulation
E509 is authorised in the EU and has been evaluated by EFSA. Open Food Facts data indicate that EFSA identified a moderate risk of some population groups exceeding the acceptable intake for this additive or the group it belongs to.
Written by the Foodlas editorial team with AI assistance and checked against EU Regulation (EC) No 1333/2008 and EFSA scientific opinions. Last reviewed: October 14, 2026.
Sources: Regulation (EC) No 1333/2008 · EFSA — Food additives · Wikidata
Common in
Products containing E509
