Talk:Tea processing

tea terms

There are different ways to classify tea, such as the degree of withering or fermentation, type of fresh tea leaf like tips and/or leaves, general color of finished tea leaf, like black tea or green tea. The defining processes below are based on the Tenfu Tea College and Lu-Yu Tea Culture Institute.

primary processing chart: [teasteps2010]

icetea (talk) 20:29, 17 June 2010 (UTC)

It what way is this chart is better than the one already there? Sjschen (talk) 21:38, 17 June 2010 (UTC)

hi; i think the original chart is good but it might be with the terminology, my knowledge of tea processing mostly comes from china/taiwan terminology, i am not an expert on japanese or indian tea processing but i think most of the processes are similar or overlap. From what i see the main diffence is in the charts is the division of steps.

• bruising: this step i include in the withering/fermentation with buising i call

laying 作青(includes setting and tossing)

setting 靜置 letting the fresh leaves rest

tossing 攪拌浪青also called shaking (but this is not rolling)

• curing: according to the chart this looks like it includes different processes, one is post-fermentation and the other is firing or what i call roasting. (i am going by the chart not the article)

this is what i would propose or something like this,(but like wiki's way we need to reach an agreement).

green tea綠茶: fixation殺青 > rolling揉捻 > drying乾燥

yellow tea黃茶: fixation殺青 > rolling揉捻 > sweltering悶黃 > drying乾燥

green Puer青普: sun fixation曬青 > rolling揉捻 > sun drying曬乾 > (usually aged)

dark tea黑茶and dark Puer熟普: sun fixation曬青 > rolling揉捻 > piling 渥堆 > sun drying曬乾

white tea白茶: withering (fermentation) 萎凋 > rolling揉捻 > drying乾燥

oolong tea烏龍茶: withering萎凋 > fermentation發酵 > fixation殺青 > rolling揉捻 > drying乾燥

black tea紅茶: withering萎凋 > rolling揉捻 > fermentation發酵 > drying乾燥

Explanation of some tea making processes:

oxidation氧化 (enzymic): a natural chemical change in the tea leaf that begins after harvesting and accelerates if leaf cells are broken and exposed to oxygen.

withering萎凋: water loss by respiration and evaporation and leaf becomes more pliable, dryness and heat aid in this process.

fermentation發酵: actually enzymic oxidation, noticeable change chemical composition and leaf becomes darker, moisture and heat aid in this process.

fixation殺青: to rapidly stop the fermentation through water loss caused by heat.

rolling揉捻: breaking the leaf cell walls exposing sap to leaf substrate and air, and shaping.

drying乾燥: making the leaves ready for storage.

Two different methods of making black tea (in India, Sri Lanka for example):

There are two methods used to rupture the leaf cells prior to fermentation.

orthodox method: the traditional way of making black tea, a batch of leaves go through the roller and are macerated and twisted.

CTC(crush-tear-cut) method: leaves are continuously fed through the machine and are rolled and go through a sharp teeth.

icetea (talk) 23:31, 17 June 2010 (UTC)

I agree with some of the changes in terminology. Namely the change with wilting and kill-green to withering and fixation, respectively. Here are my comments on the processes, which given in the parenthesis in italics:

• "fermentation發酵: actually enzymic oxidation, noticeable change chemical composition and leaf becomes darker, moisture and heat aid in this process." (The word fermentation is implies biologically driven breakdown something. However, the leaves are as you stated changed through enzymatic oxidation and as such should be listed in that manner. For this reason I prefer the term "oxidation")
• "fixation殺青: to rapidly stop the fermentation through water loss caused by heat.": (As stated I do like the use of "fixation" more than "kill-green". However, the "fermentation" is not stopped by water loss through heat but is due to the denaturing of the oxidation enzymes through heat. Proof of this is how fixation/sha-qing can be done by steaming which is a decidedly wet method.)

As for bruising and curing, although the processes included in these two groups are different, they are basically the more or less the same mode of operation in terms of the goal. this was essentially how the chart was constructed, by looking at the goal of the process rather than the actual details entailed in the process. For instance, bruising in black and oolong tea making are accomplished differently with:

• CTC Black: heavy crushing and cutting with serrated rollers
• Orthodox Black: lighter crushing with rollers
• Oolong: light damaging of the leaves around the edges to various degrees

Although all the processes are rather different, the intended result is to damage the leaf structure/cells to release the enzymes and expose the insides of the leaves to oxygen, thus contributing the production of flavour molecules. Since the goal they should be included them under the same group, namely "bruising", which is a fitting term.

The same argument goes to the curing of tea, of which one is biotic and auto-oxidation (post-fermentation) while the other is heat-based denaturing (roasting/firing). The processes are different but the intended result is to cure the teas into 熟茶, and produce something that is less astringent, less "harmful" to the gut, and more pleasant to drink (smoothness). Since the intended goal is the same, the processes are listing under the same group.

As for to splitting brusing into 3 steps (作青,靜置,浪青), to me "laying 作青(includes setting and tossing)" and "setting 靜置 letting the fresh leaves rest" are more or less withering processes, with the goal being to expel excess moisture from the leaves prior to further processing. As such, it does not contribute enough to oxidation to be listed under oxidation. "Tossing" (浪青) is neither withering nor oxidation since the process does not significantly reduce moisture nor does it contributes to oxidation (that happens after 浪青). In fact 浪青 is really there to damage the leaves to help oxidation and thus a unique step on its own, which is bruising.

For a Chinese version of the chart please look here. Perhaps you can give some comments on it too.

The description of the processing of different teas is not completely accurate when stated. My comments are given in the parenthesis in italics in the following:

• "green Puer青普: sun fixation曬青 > rolling揉捻 > sun drying曬乾 > (usually aged)"(Green pu-erh is type of green tea although sometimes technically a white tea. The aging is a curing process with auto-oxidation and biotic fermentation)
• "dark tea黑茶and dark Puer熟普: sun fixation曬青 > rolling揉捻 > piling 渥堆 > sun drying曬乾" ("dark tea" is the result of curing a finished green tea through a composting process. 渥堆 only proceeds after the a green tea is more-or less finished (not as dried))
• "white tea白茶: withering (fermentation) 萎凋 > rolling揉捻 > drying乾燥" (withering contributes only very lightly to oxidation(not fermentation))
• "oolong tea烏龍茶: withering萎凋 > fermentation發酵 > fixation殺青 > rolling揉捻 > drying乾燥"" (oolong leaves are damaged by tossing after withering, a key step of the process that is not mentioned here)

Sjschen (talk) 15:37, 18 June 2010 (UTC)

i see the chinese chart, and its terminology makes sense, i have some issues with the steps. i also see you have done much for this wiki article.

• i am looking/following the chart you provide and the list above i have copied here to try to evalutate, please make your suggestion on it. yes real fermention is not what i am using, i am using tea jargon fermention/oxidation, when i mean microbe fermention i use piling.

• "green Puer青普: sun fixation曬青 > rolling揉捻 > sun drying曬乾 > at this point it is done and can be aged but it still is green puer the thing that makes a Puer is it has to be sun fixed, the aging is an added process, yes it should be aged but it does not have to be it is still a green puer at this point. and it can be compress into cakes.
• "dark tea黑茶and dark Puer熟普: sun fixation曬青 > rolling揉捻 > piling 渥堆 > sun drying曬乾" (dark and dark puer have sun fixation, regular green tea doesnt have sun fixation)
• "white tea白茶: withering (fermentation) 萎凋 > rolling揉捻 > drying乾燥" ( yes lightly oxidation, but white tea is not high heat fixated it is withered then rolled lightly then dried, many from in fuding china)
• "oolong tea烏龍茶: withering(with buising/tossing)萎凋 > fermentation發酵 > fixation殺青 > rolling揉捻 > drying乾燥"" (you are correct the tea is bruised usually several times, but the chart has sun withering this is not an important step to oolongs, many oolongs are made with indoor withering an example cool long time withering like anshi iron goddess)

green tea綠茶: fixation殺青 > rolling揉捻 > drying乾燥(the fixation is usually pan fixation in china/taiwan and steam fixation in japan)

yellow tea黃茶: fixation殺青 > rolling揉捻 > sweltering悶黃 > drying乾燥(similar to green tea but has a added swealtering process no added heat the tea is piled up after fixation and rolling for short-time only made in the spring)

black tea紅茶: withering萎凋 > rolling揉捻 > fermentation發酵 > drying乾燥 (key point for all black teas is first rolled/ctc/rupture cell walls then fermention)

to create the varieties of tea we do not need the "curing/added process/加工" of roasting: for example if a green tea is roasted it still is a green tea like the japanese tea (Hōjicha/ほうじ茶/番茶). oolongs can be roasted but not necessary, same is for scenting and spicing. see below.

• problems of translating: taiwan and many parts of china use 初製and 加工 differently so i will put what i mean by each below:
• added processing 加工, here i mean soming added after the tea is one of the main varieties and cant be changed again example like once it is a green tea it wont change into a black tea: re-drying覆火, aging 陳放 (by storing), roasting 焙火, scenting熏花, spicing調味
• what is important is the primary processing:

Primary Processing初製from fresh leaves 茶青not all are used: withering萎凋, fermentation發酵, fixation殺青,rolling揉捻,drying乾燥, 渥堆 piling, this is the process that make a tea black or white or other variety.

i have a link to a large list of tea terms you are welcome to use them in anyway, i try to use the same chinese/english tea terms to avoid confusion. link

icetea (talk) 21:27, 18 June 2010 (UTC) the above and the current "tea processing" article is basically the same no further actions from my part as of this time. I have no objections in using or deleting the above tea terms discussion section. icetea (talk) 23:40, 21 June 2010 (UTC)