Tea Leaf

Tea is plucked from the flush — the periodic burst of new shoots the bush produces — and the plucking round returns every several days to take the new growth. What the plucker takes defines the commodity: a bud and two leaves is fine plucking, a bud and three or more leaves is coarse, and the ratio of fine to coarse in a delivered lot is what the factory assesses and pays against.

The reason is compositional. The bud and youngest leaves are richest in the compounds that make tea — the polyphenols that oxidise into the colour and briskness of black tea, and the amino acids and aromatics that carry flavour. Older leaf is fibrous, lower in those compounds, and dilutes the lot. A factory receiving coarse leaf will make a thinner, cheaper tea, and no processing skill compensates.

From the moment a shoot is plucked its cells are cut off from supply and its enzymes are active. Leaf left heaped in a sack heats from its own respiration, and heat plus pressure plus time produces exactly what tea makers do not want: uncontrolled oxidation, in the field, before any of the deliberate processing decisions have been made. The resulting made tea is flat and dull, and the fault was committed before the leaf ever reached a machine.

The chain is therefore built for speed and gentleness. Leaf goes into open, ventilated baskets or crates rather than sacks that compress it, collection points are sited close to the fields, and vehicles run frequent short trips rather than accumulating a full load. Factories are built among the tea gardens rather than at ports, which is why tea processing is an origin industry in a way that, say, cashew processing is not.

Hand plucking remains the standard for quality tea because a hand can select the shoot and leave the rest, and the pluckers move through the same field repeatedly across a season. Mechanical harvesting and shears are used where labour costs or scale demand it, and they take what they cut — bud, young leaf, old leaf, and stalk together — which coarsens the lot but transforms the economics.

At the factory gate, green leaf is weighed and assessed, usually by a visual and tactile judgement of the plucking standard and the leaf's condition. Payment on weight alone rewards volume, including the older leaf that adds weight and subtracts quality — so leaf pricing structures that reward fine plucking are one of the principal levers a tea industry has over its own quality, and they are set by country, by company, and by smallholder scheme.

Assessment covers the plucking standard, the freshness and turgidity of the leaf, the absence of heating and bruising, and freedom from foreign matter. Because the commodity cannot be stored, there is no second chance to assess it and no possibility of holding a lot until the price improves — leaf delivered is leaf processed, the same day.

• Coarse plucking — excess mature leaf and stalk diluting the lot
• Heat damage from leaf heaped or held too long before withering
• Bruising and crushing from compression in sacks or overfilled containers
• Wilting and moisture loss in leaf held in sun or wind
• Foreign matter — weeds, other species, and debris in the delivered lot
• Wet leaf plucked in rain, which mats, heats, and withers unevenly

Effectively all green leaf goes to tea manufacture, and what type of tea it becomes is a factory decision made on the same leaf: black tea through full oxidation, green tea by preventing oxidation with heat soon after plucking, and oolong, white, and dark teas through other routes. The same delivered lot could in principle become any of them, which is another way of saying that the leaf is the raw material and the tea type is manufactured. Fine plucking supplies premium whole-leaf teas; coarser leaf feeds the high-volume methods that supply blended and bagged tea.

• Beverage — manufacture into black, green, oolong, white, and dark teas
• Food and industrial — leaf and processing fractions used for extracts and instant tea