Procedure Tea_processing

type-specific

tea traditionally classified based on degree or period of fermentation leaves have undergone:

green tea
this tea has undergone least amount of oxidation. oxidation process halted quick application of heat after tea picking, either steam, method preferred in japan, or dry roasting , cooking in hot pans, preferred in chinese tea processing. tea leaves may left dry separate leaves or may rolled small pellets make gunpowder tea. process time consuming , typically done pekoes of higher quality. tea processed within 1 2 days of harvesting, , if done correctly retains of chemical composition of fresh leaves produced. variation in steaming time fixation or processing additional stages of rolling , drying used improve or altering flavour types of green tea. green tea leaves undergo fixation either roasting (panning) or steaming. generally, roasted varieties richer in flavor, while steamed varieties more vivid in color.
yellow tea
this tea processed in similar manner green tea, instead of immediate drying after fixation, stacked, covered, , gently heated in humid environment. initiates oxidation in chlorophyll of leaves through non-enzymatic , non-microbial means, results in yellowish or greenish-yellow colour.
white tea
young leaves or new growth buds have undergone limited oxidation through slight amount of withering while naturally sun dried or withered , halting oxidative processes baking optimal withering conditions @ 30 degrees celsius (65% relative humidity) 26 hours. withering of leaves can last around 1 3 days depending on season , temperature of processing environment. buds may shielded sunlight prevent formation of chlorophyll. tea leaves meant white teas not kneaded nor undergo fixation, preserves of white hair on leaves , gives tea relatively mild flavour. white tea produced in lesser quantities other styles, , can correspondingly more expensive tea same plant processed other methods. less known in countries outside of china, though changing increased western interest in tea. there international disagreement on definition of white tea between china , other producing countries, in china term applied tea varieties made through white tea process while in other countries term used teas made through process.
oolong tea
this tea s oxidation stopped somewhere between standards green tea , black tea. processing typically takes 2 3 days withering drying relatively short oxidation period of several hours. in regard, darjeeling teas light oxidation levels more similar green or oolong teas. in chinese, semi-oxidized teas collectively grouped blue tea (青茶, literally: blue-green tea / celadon tea ), while term oolong used name semi-oxidized teas. common wisdom lightly oxidized teas in taiwan (a large producer of oolong) little oxidation upsets stomach of consumers. so, producers attempt minimize oxidation in order produce specific taste or allow tea leaves rolled spherical or half-sphere form demanded buyers in market.
black tea
the tea leaves allowed oxidize. black tea first withered induce protein breakdown , reduce water content (68-77% of original). leaves undergo process known in industry disruption or leaf maceration , through bruising or cutting disrupts leaf cell structures, releasing leaf juices , enzymes activate oxidation. oxidation process takes between 45–90 minutes 3 hours , done @ high humidity between 20-30 degrees celsius, transforming of catechins of leaves complex tannin. orthodox processed black teas further graded according post-production leaf quality orange pekoe system, while crush, tear, curl (ctc) teas use different grading system. orthodox tea leaves heavily rolled either hand or mechanically on cylindrical rolling table or rotorvane. rolling table consists of ridged table-top moving in eccentric manner large hopper of tea leaves, of leaves pressed down onto table-top. process produces mixture of whole , broken leaves, , particles sorted, oxidized, , dried. rotovane consisted of auger pushing withered tea leaves through vane cylinder crushes , evenly cuts leaves. crush, tear, curl production method developed william mckercher in 1930 uses machines contra-rotating rotors surfaces patterning cut , tear leaves producing product popular use in tea bags. rotovane use precut withered tea prior ctc , create broken orthodox processed black tea.
post-fermented tea
teas allowed undergo second oxidation after fixation of tea leaves, such pu-erh, liu an, , liubao, collectively referred secondary or post-fermentation teas in english. in chinese categorized dark tea or black tea. not confused english term black tea, known in chinese red tea. pu-erh, known póu léi (polee) in cantonese common type of post-fermentation tea in market.