Matcha muffin with sweetened azuki beans.jpg

is finely ground powder of specially grown and processed green tea leaves, traditionally consumed in East Asia. The green tea plants used for matcha are shade-grown for three to four weeks before harvest; 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, as it 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 spirituality. In modern times, matcha is also 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, meaning that the powder is of a high enough quality to be used in the tea ceremony. Lower-quality matcha is referred to as culinary-grade, but no standard industry definition or requirements exist for matcha.

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''.

History

In China during the Tang dynasty (618–907), tea leaves were steamed and formed into tea bricks for storage and trade. The tea was prepared by roasting and pulverizing the tea, decocting the resulting tea powder in hot water, and then adding salt. During the Song dynasty (960–1279), the method of making powdered tea from steam-prepared dried tea leaves and preparing the beverage by whipping the tea powder and hot water together in a bowl became popular.Tsutsui Hiroichi, "Tea-drinking Customs in Japan", paper in ''Seminar Papers: The 4th International Tea Culture Festival''. Korean Tea Culture Association, 1996.

Preparation and consumption of powdered tea was formed into a ritual by Chan Buddhists. The earliest extant Chan monastic code, titled ''Chanyuan Qinggui'' (''Rules of Purity for the Chan Monastery'', 1103), describes in detail the etiquette for tea ceremonies.

Zen Buddhism and methods of preparing powdered tea were brought to Japan by Eisai in 1191. In Japan, it became an important item at Zen monasteries, and from the 14th through the 16th centuries, it was highly appreciated by members of the upper echelons of society.

Production

Matcha is made from shade-grown tea leaves that also are used to make ''gyokuro''. The preparation of matcha starts several weeks before harvest and may last up to 20 days, when the tea bushes are covered to prevent direct sunlight. This slows down growth, stimulates an increase in chlorophyll levels, turns the leaves a darker shade of green, and causes the production of amino acids, in particular theanine. After harvesting, if the leaves are rolled up before drying as in the production of '' sencha'' (煎茶), the result will be ''gyokuro'' (jade dew) tea. If the leaves are laid out flat to dry, however, they will crumble somewhat and become known as ''tencha'' (). Then, ''tencha'' may be deveined, destemmed, and stone-ground to the fine, bright green, talc-like powder known as ''matcha''.

Grinding the leaves is a slow process because the mill stones must not get too warm, lest the aroma of the leaves be altered. Up to one hour may be needed to grind 30 grams of matcha.

The flavour of matcha is dominated by its amino acids. The highest grades of ''matcha'' have a more intense sweetness and deeper flavour than the standard or coarser grades of tea harvested later in the year.

''Tencha''

''Tencha'' refers to green tea leaves that have not yet been ground into fine powder as ''matcha'', as the leaves are instead left to dry rather than be kneaded. Since the leaves' cell walls are still intact, brewing tencha tea results in a pale green brew, which has a more mellow taste compared to other green tea extracts, and only the highest grade of ''tencha'' leaves can brew to its fullest flavor. ''Tencha'' leaves are half the weight of other tea leaves such as ''sencha'' and ''gyokuro'' so most ''tencha'' brews require double the number of leaves. About an hour is needed to grind 40 to 70 g of ''tencha'' leaves into matcha, and matcha does not retain its freshness as long as ''tencha'' in powder form because powder begins to oxidize. Drinking and brewing ''tencha'' is traditionally prohibited by the Japanese tea ceremony.

Grades

Commercial considerations, especially outside Japan, have increasingly seen matcha marketed according to "grades", indicating quality.

Of the following terms "ceremonial grade" is not recognised in Japan but "food grade" or "culinary grade" are.
* Ceremonial grade designates tea for its use in tea ceremonies and Buddhist temples. All must be able to be used in koicha (濃茶), a "thick tea" with a high proportion of powder to water used in traditional tea ceremony.
* Premium grade is high-quality matcha green tea that contains young tea leaves from the top of the tea plant. Best for daily consumption, it is characterized by a fresh, subtle flavor, usually perfect for both new and everyday matcha drinkers alike.
* Cooking/culinary grade is the cheapest of all. Suitable for cooking purposes, smoothies etc. It is slightly bitter due to factors such as its production from leaves lower down on the tea plant, terroir, the time of harvest, or the process of its manufacture.

In general, matcha is expensive compared to other forms of green tea, although its price depends on its quality. Higher grades are pricier due to the production methods and younger leaves used, and thus they have a more delicate flavour, and are more suited to be enjoyed as tea.

Like other forms of green tea, all grades of matcha have the potential health benefits and risks associated with the ''Camellia sinensis'' plant (the human clinical evidence is still limited), while the nutrient content varies depending on climate, season, horticultural practices, plant variety, manufacturing methods and the age of the leaf, i.e., the position of the leaf on the harvested shoot. Catechin concentration is highly dependent on leaf age (the leaf bud and the first leaf are richest in epigallocatechin gallate