Citric acid is the dominant food acid — the clean, bright sourness behind soft drinks, sour candies and countless sauces. A weak organic acid that occurs naturally in citrus fruit, it is used to add tartness, lower and control pH, slow browning and rancidity as an antioxidant helper, and (as its salt, sodium citrate) to buffer and sequester. It is odourless and adds only sourness, no flavour of its own.
PAIR's modernist science — how much to use, how it behaves with heat, and what makes it fail — is a Pro feature. The description, nutrition, history and facts stay free.