Goishicha

Where it grows

The districts recorded against this tea, all of them in Japan. Elevation is given as the band the district is recorded at, not a measurement of the garden this leaf came from.

• Ōtoyo — 200–700 metres

  How firm this is: Inferred from general knowledge of the district rather than measured or taken from a source that states it.

The plants it is made from

Cultivar is the level below the variety group: a named selection of the tea plant, propagated as clones from one parent. Most consumer writing stops at the country and the category, which leaves out the layer that decides how the leaf behaves before anyone picks it.

Japan's agriculture ministry gives the raw material as two kinds of yamacha — naturalised mountain-tea stands, historically post-swidden — and Yabukita. The zairai link stands in for the yamacha half because TeaHQ has no record for two stands in one Kochi valley, and the two are not quite the same thing.

• Yabukita — Camellia sinensis var. sinensis

  Balanced rather than distinctive: a dependable base for sencha, which is precisely why it was planted so widely.

• Zairai — Camellia sinensis var. sinensis

  Variable leaf, deep taproots from seed, late budding and low yield. Frost-hardier than many named cultivars and often found on marginal or abandoned plots.

How it is made, in order

Read top to bottom: the list is the production sequence, and the sequence is what makes this tea its category rather than a neighbouring one. The same leaf from the same bush becomes a green tea or a black tea depending on where the heat falls relative to the bruising, so reordering these steps would not vary the tea — it would produce a different one.

1. 1. Steaming (Japanese fixation) — Denatures polyphenol oxidase using saturated steam, arresting oxidation without applying dry contact heat to the leaf surface.
2. 2. Wet piling (wo dui) — Supports microbial and thermal transformation of the finished leaf, converting harsh young character into a darker, softer profile.
3. 3. Anaerobic pickling — Excludes oxygen from a mass of heat-treated leaf so that lactic acid bacteria dominate the microbial population, acidifying the leaf and transforming it under anaerobic conditions.
4. 4. Compression — Reduces the leaf’s exposed surface area and fixes it in a stable physical form, slowing and evening out subsequent change.
5. 5. Sun-drying (shai qing) — Reduces moisture to a storable level at low temperature, leaving residual enzymatic and microbial activity in the leaf.

The route it is made by

The steps above are what happens; this is the named production route they belong to, with the other teas made the same way.

• Anaerobic pickled tea — The shortest dark tea route and the only one that excludes air. Air is what every other fermentation in tea depends on, and removing it changes which organisms do the work.

  Where it is practised: Kochi and Tokushima in Japan, and upland northern Thailand, Myanmar and Laos, where pickled tea is as often eaten as brewed and where that is the older documented use.

What its chemistry turns on

Every true tea contains caffeine, catechins and amino acids, so listing them would say nothing about this one. What differs is what the processing above does to them — and that is the same list of steps, read for its chemistry instead of its craft.

The compounds that substantially decide what this tea is: Organic acids.

• Steaming (Japanese fixation)
  • creates Dimethyl sulfide
  • lowers Green-leaf volatiles
  • locks Chlorophyll
  • locks EGCG (epigallocatechin gallate)
• Wet piling (wo dui)
  • converts Catechins
  • creates Gallic acid
  • creates Theabrownins
  • raises Organic acids
  • raises Pectins
  • lowers ECG (epicatechin gallate)
  • lowers Soluble sugars
• Anaerobic pickling
  • creates Organic acids
• Sun-drying (shai qing)
  • raises Beta-ionone
  • lowers Carotenoids

These are statements about the leaf and the cup. What any of these compounds does in a body is a different kind of question and is not answered here or on the pages linked from it.

History

A twice-fermented tea from Kochi that came close to disappearing in the twentieth century, sustained by a handful of producers. It is one of very few genuinely fermented teas outside China and its survival was not assured.

TeaHQ synthesis — TeaHQ's own reading of well-attested general knowledge, with no single source behind it.

Brewing

• Boiling and decoction

  0.5–1.5 g/100 ml · 95–100 °C · 1 authored infusion

  Open in the brew assistant

• Western brewing (teapot or mug)

  1.5–2.5 g/100 ml · 95–100 °C · 1 authored infusion

  Needs: Western teapot

  Open in the brew assistant

• Boiling aged and dark tea (zhu cha)

  0.8–1.5 g/100 ml · 95–100 °C · 1 authored infusion

  Needs: Kettle, Brewing saucepan, Tea strainer

  Open in the brew assistant

When the cup goes wrong

Written against dark tea and pu-erh as a category rather than against this tea in particular, and worked back from the symptom to the likely causes in order. 15 apply to the category; the first 6 are shown.

• Every infusion in my gongfu session tastes the same — The cups are pleasant and interchangeable, with none of the change from steep to steep the method is supposed to show.
• My clay pot has changed how the tea tastes — A tea that tasted right in porcelain comes out muted, differently scented, or carrying something that was not in the leaf.
• My first infusion is always the worst one — The opening cup is thin, dusty or flat, and the second is markedly better — consistently, across different teas.
• My gaiwan is too hot to hold — The rim and lid become uncomfortable within seconds, the pour is rushed, and tea ends up on the tray.
• My gongfu tea is bitter even at five seconds — The timer says five or ten seconds and the cup is over-extracted anyway, with the later infusions dropping off sharply.
• My pu-erh cake will not break apart cleanly — The cake resists the pick, then gives way suddenly into powder and fragments rather than intact leaf.

Every diagnosed brewing problem

If you like this

Grouped by why they were suggested, strongest reason first. Nothing here is a blended score — a suggestion appears under the best reason that exists for it, and never under a weaker one as well.

Compare this tea with another

Written comparisons

Where TeaHQ has set this tea against another in full, rather than deriving the comparison. Each one is a written page with the points of difference argued out.

• Three teas called fermented, three different processes — 'Fermented' is used for so many different operations in tea that the word has stopped carrying information. These three genuinely are fermented, by three different routes, and only one of them is what most people mean by the term. Put the two side by side

Guides covering this tea

• Acids and sourness: when it is a fault, when it is a feature