Tea 101
Tea Processing Steps
The six stages of tea processing: plucking, withering, rolling, oxidation, fixation, and drying. How each step shapes the flavor of your cup.
Introduction
Every tea passes through some combination of six fundamental processing steps. The specific sequence, duration, and intensity of each step — combined with the raw material quality — determines the character of the finished tea.
1. Plucking
Harvesting sets the quality ceiling. The standard plucking grade is the bud and two leaves (yi ya er ye), though premium teas may use bud-only or bud-and-one-leaf. Machine harvesting, common in Japan and Kenya, sacrifices selectivity for efficiency.
2. Withering
Fresh leaves contain 75-80% moisture. Withering on bamboo trays or ventilated troughs over 12-18 hours reduces moisture to 60-65%, making leaves pliable for rolling. During withering, chemical changes begin: caffeine increases, chlorophyll starts breaking down, and aromatic compounds begin developing. The withering room's temperature and humidity profoundly affect the finished tea.
3. Rolling (or Shaping)
Rolling ruptures cell walls, releasing enzymes and juices that initiate oxidation. The intensity varies dramatically: gentle hand-rolling for white tea, moderate machine rolling for orthodox black tea, and aggressive CTC crushing for tea bag grades. Some oolongs undergo repeated cycles of rolling and resting to build complexity.
4. Oxidation
After rolling, leaves are spread in a cool, humid environment where {{glossary:oxidation}} proceeds at a controlled rate. The tea maker monitors color change, aroma development, and leaf temperature to determine when to halt the process. This step is entirely skipped for green tea and extended to completion for black tea.
5. Fixation (Kill-Green)
Heat application denatures the polyphenol oxidase enzyme, freezing the oxidation level at the desired point. Pan-firing (Chinese method) produces a toasty, nutty character. Steaming (Japanese method) preserves a brighter, more vegetal profile. The choice of fixation method is one of the most consequential decisions in tea processing.
6. Drying
Final drying reduces moisture to 3-5% for shelf stability. Methods include hot-air tumble dryers, charcoal roasting (traditional), and sun drying (certain white teas). Over-drying scorches volatile aromatics; under-drying risks mold during storage.
The Art and Science
Processing is where tea becomes an artisan craft. The same fresh leaves, processed by different tea makers, will produce distinctly different teas. Variables like ambient humidity, the maker's experience, and even the wood used for charcoal drying create the infinite diversity of the tea world.