Ascorbic acid is vitamin C in its pure crystalline form — a white, water-soluble, mildly tart powder that doubles as one of the kitchen's most useful antioxidants. A pinch dissolved in water keeps cut apples, pears, avocado and artichokes from going brown, brightens and tightens bread dough, and adds a clean sour note where you want acidity without a fruit's flavour.
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.