Which amino acid gives tea its umami flavor?

L-theanine is the amino acid associated with tea’s savory, umami character. It is a non-protein amino acid produced naturally by the tea plant, Camellia sinensis, and is especially notable in green teas.

Theanine was identified in tea in 1949 and isolated from gyokuro, a shaded Japanese green tea, in 1950. Shading tea plants reduces sunlight exposure and generally increases their theanine content, which helps explain the rich, brothy taste of gyokuro and matcha.

Tea’s flavor is not produced by one compound alone. Glutamate, sugars, minerals, caffeine, catechins, and aromatic compounds also contribute, and brewing method changes the balance. Glutamic acid is commonly associated with umami in foods, but L-theanine is the tea-specific answer intended by this question. The name is sometimes written simply as theanine, although naturally occurring tea contains primarily the L form.