matcha
ingredient / ingredient-matcha
抹茶
Powdered green tea made by milling tencha into a very fine powder with a tea mill or similar device. Besides serving as the ingredient for koicha and usucha in the tea ceremony, it is also used as a secondary ingredient in foods and beverages.
Photographs (captions in Japanese)
A heaped spoonful of bright green matcha powder. Powder has also spilled around it.
Prepared formShown: Camellia sinensis (matcha, tencha ground to a fine powder)Part / state: Fine powdered tea
Photo: Evanhoever / CC BY-SA 4.0 / original image / ledger's original image
Scope and provenance of the photo
Identification: Identified as labelled in the source. The description is only "A scoop of Matcha". No origin or grade is given. I opened the image and confirmed the uniform green fine powder heaped on a spoon and how it is scattered.
Image shown: The original from Wikimedia Commons, reduced to 2400 px on the long side. No cropping or color changes. For display, a WebP capped at 1200 px wide is served; the ledger's original image can be checked from the link above.
On this page (8 sections)
Reading the bitterness
The Japan Tea Central Association defines matcha as tencha, tea leaves grown under cover and dried without rolling, milled to a very fine powder with a tea mill or similar device. Explanations by 「裏千家」 (Urasenke) and academic papers also follow this definition. Matcha for processed foods is described as accounting for most production. Research and industrial practice has confirmed that tencha is milled with several types of equipment, including not only traditional stone mills but also ball mills, jet mills, and water-cooled metal mills.
Findings on catechin composition and sensory scores under covered cultivation are separate. A conference abstract cites earlier findings that covering reduces epigallocatechin (EGC), which has relatively weak bitterness and astringency, but produces almost no detectable reduction in epigallocatechin gallate (EGCG), which has stronger bitterness and astringency. In a fiscal 2016 Shizuoka Prefectural Research Institute of Agriculture and Forestry trial with first-flush 「やぶきた」 (Yabukita) tea, stronger and longer covering raised the combined dry-weight content of the 7 principal free amino acids in tencha from 0.844% without covering to a maximum of 2.364%. The sensory score for matcha, a composite of color and luster, foaming, foam color, and taste out of 100 points, rose from 54 without covering to a maximum of 76. This was a composite sensory score, however, not a separate measure of bitterness alone.
The question of why matcha tastes less bitter and astringent than its leaf constituent content would suggest has also been investigated. In a matcha infusion prepared in line with the method used for sensory assessment, extraction rates for theanine, caffeine, and EGC were at least 80%, whereas that for EGCG remained at or below 50%; EGCG concentration in the infusion was reported to be lower than in sensory-assessment infusions of sencha and other teas. The authors propose that vigorous whisking when preparing matcha rapidly lowers the water temperature, impeding dissolution of the highly temperature-dependent EGCG into the water. This is an interpretation based on measured data, however, not an experiment that directly measured the water temperature itself.
A hypothesis that the foam produced during whisking adsorbs EGCG and other bitter-astringent constituents and thus reduces the infusion’s bitter-astringent taste has also been tested. The same authors found no significant difference when they compared tea constituent concentrations before and after foaming, so the foam-adsorption hypothesis was not supported. Foam appears to play a small role in why matcha tastes less bitter than its leaf content would predict.
Sources for this overview
Checked for this overview: Used as evidence for the definition of matcha as milled tencha.
粒度と食感からみた抹茶のおいしさ (The Mouthfeel of Matcha from the Viewpoint of Particle Size and a Texture)
Checked for this overview: Used as the citation basis for the industry association’s official definition. / Used as evidence of milling with multiple kinds of equipment.
Checked for this overview: Used as evidence of milling with a water-cooled metal mill. / Used as evidence for the amino acid and sensory-score data under different covering conditions.
抹茶の点て方に関する化学的考察 (Chemical research on the preparation of matcha)
Checked for this overview: Used as evidence for the different responses of EGC and EGCG to covering. / Used as evidence for the measured low extraction rate of EGCG. / Used as evidence for the proposed decline in water temperature from whisking. / Used as evidence for the negative result on the foam-adsorption hypothesis.
Hypotheses and recipe candidates for this entry are on the Japanese page.
Structured claims — open a section to read each claim's confidence, evidence and limits
Composition and content (2)
Scope: Matcha made from tencha (shading cultivation)
Note: This is background text in the "Purpose" paragraph of a NARO (National Agriculture and Food Research Organization) conference abstract, stated as a summary of prior knowledge rather than new measurement data from the abstract itself (citation numbers are not given in the abstract). Figures such as the rate of change in EGC and EGCG content are not given in this abstract.
Show data
ingredient-matcha —has_composition→ (the claim sentence above)Scope: Matcha (prepared according to the method used for sensory panels)
Note: A measured value obtained by directly analyzing the centrifuged supernatant with capillary electrophoresis and high-performance liquid chromatography.
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ingredient-matcha —has_composition→ (the claim sentence above)Mechanism and receptors (2)
Scope: Matcha (whisked according to the method used for sensory panels)
Note: The authors' own interpretation; the abstract does not present an experiment that directly measured the water temperature itself, nor a causal experiment involving sensory evaluation of the bitter-astringent taste. An interpretation derived from measured extraction-rate data (in which only EGCG is low).
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ingredient-matcha —has_perceived_bitterness_suppressed_by→ (the claim sentence above)Scope: Matcha prepared by a method corresponding to that used for sensory assessment.
Note: The authors tested and rejected the hypothesis 『泡がEGCG等の苦渋味成分を吸着するため抹茶は苦渋くない』 (in translation: "Matcha is not bitter and astringent because foam adsorbs EGCG and other bitter-astringent constituents"); this negative finding is based on direct measurement.
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ingredient-matcha —has_perceived_bitterness_unchanged_by→ (the claim sentence above)How processing and cooking change it (5)
Note: Confirmed from both the Japan Tea Central Association's definition (tencha ground finely with a tea mill or similar device) and the Urasenke site's explanation of the process.
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ingredient-matcha —is_prepared_from→ ingredient-tenchaNote: Matcha results from finely milling finished tencha with a stone mill or similar device. In research and food processing, however, metal mills, ball mills, and jet mills are also used.
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ingredient-matcha —is_processed_by→ process-matcha-millingScope: Tea Research Center, Shizuoka Prefectural Research Institute of Agriculture and Forestry; first-flush 「やぶきた」 (Yabukita) tea; fiscal 2016 trial.
Note: This primary source links both constituent (free amino acid) and sensory-score data within the same trial design. The sensory score, however, combines categories including 『滋味』 (in translation: "taste") and is not a separate measure of bitterness alone.
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ingredient-matcha —has_composition→ (the claim sentence above)Scope: Matcha made by milling tencha of a level used for tea-ceremony practice with different devices. For sensory evaluation, 2 g of matcha was mixed with 80 mL of hot water using an electric whisk; 3–5 people evaluated the samples multiple times.
Note: The paper’s main point is that texture depends not only on median diameter but also on the shape of the particle-size distribution, including the ratio of bimodal peaks and the 90% maximum diameter. It also cites earlier general findings from chocolate and other research that the boundary for perceiving graininess is a median diameter of 20–30 μm.
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ingredient-matcha —has_composition→ (the claim sentence above)Scope: The official general-audience explanation by 「裏千家」 (Urasenke), a school of the tea ceremony.
Note: This is a school’s explanation, not a measurement or standard. Its units differ from those in the 「上田宗箇流」 (Ueda Sōko school) explanation (3 heaped scoops) and a 「表千家」 (Omotesenke) instructor’s website (approximately 2 times as much for usucha), so the figures cannot be compared directly.
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ingredient-matcha —has_reported_preparation_style_of→ (the claim sentence above)