Turmeric gets its bright yellow color from a pigment called curcumin, which is also used as a dye.

The longer version

Curcumin is a polyphenol pigment produced in the rhizome of a ginger-family plant, and it absorbs light in a way that makes it appear vivid yellow-orange. Because the molecule dissolves readily in fats but poorly in water, it behaves as a dye rather than as a flavor, staining whatever it touches with only a small amount.

Its color shifts with acidity, turning more reddish under alkaline conditions while staying bright in acid, which is one reason it has long served as a simple chemical indicator as well as a colorant. Ground turmeric also loses intensity slowly when exposed to light, since the pigment breaks down over time.

Where this entry sits

Everyday ingredients turn out to be full of quiet chemistry and long history. This collection gathers short, plain explanations of how bread rises, why onions sting, where common spices originate, and how coffee, tea, and chocolate reached the modern kitchen. The full list sits on the Food and Drink page, where every entry is listed in order.