awa bancha boil-then-lactic fermentation
process / process-awa-bancha-fermentation
阿波晩茶の一段階乳酸発酵
Awa bancha boil-then-lactic fermentation is a post-fermentation step in making Awa-bancha. Heat treatment, such as boiling the tea leaves in a large cauldron, first prevents oxidative fermentation; the leaves are then packed into vats or barrels for a single stage of lactic acid fermentation alone. It differs from the two-stage fermentation of Goishicha and Ishizuchi-kurocha in that it has no mold-inoculation step.
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Reading the bitterness
Awa-bancha production begins by heat-treating tough tea leaves harvested late in summer, for example by boiling them in a large cauldron, to stop oxidative fermentation. The steps proceed in this order: picking, boiling, rubbing, packing for fermentation, drying, and sorting the tea. Packing the boiled leaves in vats or barrels promotes only a new lactic acid fermentation, without a mold-inoculation step involving filamentous fungi, resulting in a single stage of post-fermentation.
This production method was designated an Important Intangible Folk Cultural Property under the title 『阿波晩茶の製造技術』 (in translation: "Manufacturing technique of Awa-bancha") on March 11, 2021. It is transmitted in 3 towns in Tokushima Prefecture: Kamikatsu in Katsuura District, Naka in Naka District, and Minami in Kaifu District. The protecting organizations are the Awa Bancha Manufacturing Technique Preservation Societies in the respective towns.
In a peer-reviewed study comparing hot-water infusions under the same conditions (1.5 g of tea leaves in 100 mL of boiling water for 5 minutes), unfermented green tea contained 43.7 mg/100 mL caffeine and 87.8 mg/100 mL total catechins, whereas 2 Awa-bancha samples from different producers contained only 3.8–6.1 mg/100 mL caffeine and 7.9–9.7 mg/100 mL total catechins. Of the 4 post-fermented teas compared in that same paper, Awa-bancha had the lowest catechin concentration.
Sources for this overview
Checked for this overview: Confirmed the single-stage process in which boiling stops oxidative fermentation and packing promotes only lactic acid fermentation, along with the sequence from tea picking through sorting. / Confirmed the designation name and date, 3 transmitting towns, and protecting organizations in the original Agency for Cultural Affairs record.
Comparison of antioxidant activities among four kinds of Japanese traditional fermented tea
Checked for this overview: Measured caffeine and catechin concentrations compared with the green-tea control.
Follow the connections
awa bancha boil-then-lactic fermentation →reduces→ tea catechins →are main contributors to→ astringency
Structured claims — open a section to read each claim's confidence, evidence and limits
How processing and cooking change it (2)
Scope: Kamikatsu, Naka, and Minami, Tokushima Prefecture
Note: Included after directly checking the original record in the Agency for Cultural Affairs' 「文化遺産オンライン」 (in translation: "Cultural Heritage Online") (heritage id 541631).
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process-awa-bancha-fermentation —is_prepared_by→ (the claim sentence above)Scope: Layer: Food. Green tea (unfermented, control) and Awa-bancha (2 samples from different producers) extracted under identical conditions (hot water 100 mL, 1.5 g leaf, 5 minutes), n=5 comparison.
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process-awa-bancha-fermentation —reduces→ compound-catechinsSafety and regulation (1)
Scope: Kamikatsu, Naka, and Minami, Tokushima Prefecture
Note: Included after directly checking the original record in the Agency for Cultural Affairs' 「文化遺産オンライン」 (in translation: "Cultural Heritage Online") (heritage id 541631).
Show data
process-awa-bancha-fermentation —is_registered_as→ (the claim sentence above)