Tea Processing
A great overview over tea processing gives Laura Martin's "Tea: The Drink That Changed the World". Follow this link for the Google Books extract.
- Green Tea: Ancient China, mature leafs were steam, then dried; later: pulverised after steaming, then pressed into tea bricks
- Yellow / Fermented Tea: if oxidation is not stopped quickly enough (steamed too long, not cooled quickly enough); if tea is left in piles —> microbial fermentation; now sometimes used deliberately to make teas such as Pu-erh
- Oolong / White Tea: withering process important, delicate buds used for producing white tea
- Black Tea: full oxidation
General Process
- Plucking: picking of tea flushes (tea bud + young leaves) up to four times per year from early spring to late summer (rarely autumn or winter)
- Withering: left in sun or cool breezy room to wither: pulls water out of tea, allows for oxidation
- Disruption: bruising or tearing of leaves to quicken oxidation, —> breaks down structures within leaf, allows oxidative enzymes to mix with various substrates + releases juices that aid oxidation
- Oxidation/ Fermentation: chlorophyl in leaves is broken down and tannins are released/transformed
source: Lifehacker
Taste
Taste buds (papillae) of the tongue (physical separation of taste buds on tongue is disputed):
Other factors
- bitter
- salty
- sour
- sweet
- umami
Other factors
- smell
- astringency: phenolics
- umami - theanine
- florar - fruity volatiles
- caffeine
Components of Tea
- Cholorophyl makes tea green
- Tannins - Phenols = class of chemicals in hexagonal shape, the bigger the phenols (linked up by enzymes) the more light it absorbs, makes tea bitter, astringent, dissolve at higher temperatures
- amino acids dissolve at lower temperatures than tannins, most flavoursome