Matcha is finely ground powder of specially grown and processed green tea leaves. It is special in two aspects of farming and processing: the green tea plants for matcha are shade-grown for three to four weeks before harvest, and the stems and veins are removed during processing. During shaded growth, the plant Camellia sinensis produces more theanine and caffeine. The powdered form of matcha is consumed differently from tea leaves or tea bags, and is suspended in a liquid, typically water or milk.
The traditional Japanese tea ceremony centers on the preparation, serving, and drinking of matcha as hot tea and embodies a meditative spiritual style. In modern times, matcha has also come to be used to flavor and dye foods such as mochi and soba noodles, green tea ice cream, matcha lattes, and a variety of Japanese wagashi confectionery. Matcha used in ceremonies is referred to as ceremonial-grade matcha, meaning that the matcha powder is of a high enough quality to be used in the tea ceremony. Lower quality matcha is referred to as culinary-grade matcha, but there is no standard industry definition or requirements for either.
Blends of matcha are given poetic names known as chamei (“tea names”) either by the producing plantation, shop, or creator of the blend, or by the grand master of a particular tea tradition. When a blend is named by the grand master of a tea ceremony lineage, it becomes known as the master’s konomi.
As matcha is a concentrated form of green tea, it has been long reputed by matcha enthusiasts for centuries that matcha possesses stronger health benefits associated with green tea, and such effects have not been scientifically proven until recently. Caffeine is more concentrated in matcha, which Japanese Zen monks have utilized to stimulate awakeness, but the main matcha constituent expected to have a stress-reducing effect is theanine. Theanine is the most abundant non-protein amino acid in green tea and is what gives matcha its umami flavor. The preparation of matcha requires the tea leaves to be protected from sunlight, resulting in reduced biosynthesis of theanine into catechin and a higher concentration of theanine than in traditional green tea brewing.
Theanine’s stress-reducing effects were tested at Japan’s University of Shizuoka, School of Pharmaceutical Sciences, where studies show that lab mice which consumed more than 33 mg/kg of matcha had significantly suppressed adrenal hypertrophy, a symptom that shows sensitivity to stress. The School of Pharmaceutical Sciences also tested the stress-reducing effects on university students and confirmed that students who ingested 3 grams of matcha in 500ml of room temperature water had reduced anxiety (state-trait anxiety inventory or STAI), than students who consumed fake placebo-matcha. Green tea leaves also contain the catechin, epigallocatechin gallate, an antioxidant which is evidenced to be able to mildly prevent cancer, diseases, and aid in weight loss.
As mentioned before, matcha is a higher concentration of green tea and contains caffeine, so the health risks associated with caffeine like increased heart rates can also apply to matcha if over ingested. Green tea leaves also absorb heavy metals from ground soil like aluminum, which can accumulate in the body and cause neurological damage. The study of matcha’s health effects is also limited, so further investigation is required.