Steam duration is the first axis
Asamushi, lightly steamed for around thirty seconds, gives clear liquor and needle-like leaf with more aroma. Fukamushi, deep-steamed for up to two minutes, breaks the leaf down and gives a cloudy, dark green, full-bodied cup with less aroma and more weight. The cloudiness is intended, not a filtering fault, and it is the fine particles that carry the body.
Shading is the second
Covering the bushes before picking shifts the leaf towards savoury depth and away from astringency. Unshaded gives sencha. A week or two gives kabusecha. Three weeks or more gives gyokuro when rolled, and tencha — the material for matcha — when left unrolled. This happens in the field rather than the factory, and no amount of processing can add it afterwards.
The by-products are the value
Japanese refining sorts the crop, and what is sorted out is sold separately and cheaply. Kukicha is stems, sweeter and creamier than leaf. Mecha is buds, more concentrated than the sencha it came from. Konacha is fines, strong and brisk, and is the tea in sushi restaurants. Aracha is the unrefined state before any of this. All are good value, and none is a lesser version of anything.
A route through it
Hojicha or genmaicha to start. Then sencha, which is the reference. Then kabusecha for a first taste of shading. Then fukamushicha for the deep-steamed style. Then gyokuro, and matcha last. Along the way, kukicha is worth trying purely because it is unlike anything else and costs very little.
Where blending fits
Most Japanese tea reaching consumers is blended by a merchant from several producers' aracha to a house profile that stays consistent year to year. That is standard practice rather than a compromise, and it is why single-farm Japanese tea is marketed as unusual — the opposite of the Chinese convention.