Matcha is a finely ground powder made from specially cultivated green tea leaves from the tea plant (Camellia sinensis). Before harvest, the plants are shaded to alter the chemistry of the leaves, increasing compounds such as L-theanine and chlorophyll. The youngest leaves are harvested, steamed to limit oxidation, dried, and traditionally stone-ground into a fine green powder. Because the entire powdered leaf is consumed rather than steeped and discarded, matcha provides a concentrated source of tea catechins and other bioactive compounds.

Matcha has a rich, grassy flavor with subtle sweetness and a savory quality known as umami. High-quality matcha is prized for its brilliant green color, smooth texture, and balance of L-theanine and caffeine. Its signature phytonutrient is EGCG, a catechin studied for its antioxidant, cellular-signaling, cardiovascular, metabolic, and inflammation-modulating effects. Matcha also contains quercetin, other catechins, chlorophyll, and naturally occurring caffeine.