I stumbled into a presentation on tea at a tea festival a number of years ago. I keep meaning to figure out which notebook my notes are in and make copies because it was so good. The presenter was this elderly British gent with a background in operations who got sent out to figure out how to boost tea output.
There were a bunch of charts about time and temperature and humidity for various types of tea but the biggest fact was slightly buried. 'fermentation' with respect to tea is a bit of a euphemism. It's actually autolysis. The big epiphany moment for me was connecting the dots and seeing why that was the case. Caffeine is an insecticide. It's stored in little crystals in the tissue. With oxalic acid, the crystals are the point. They're sharp and they damage the attacker.
With caffeine it's metabolic disruption. Within other organelles in the tea leaf are enzymes that can decompose the caffeine crystals into a solluble form. These chemicals only mix when the leaf is bruised, or masticated. They are booby trapped.
When you process camellia sinensis into tea, the oldest process is matcha, which started in China and is now mostly preserved in Japan, is drying the leaves and then powdering them, which I presume frees up some of the caffeine simply by mechanical decomposition. For the others the leaves are processed by bruising, heating and drying the leaves, and the order and duration dictates which kind of tea you get, and how much of the caffeine has been converted to a form that is water soluble. Black tea is aged longer, and has more available caffeine.
Almost none of them are actually fermented as in beer (puehr is the most notable, and the common reaction upon smelling it is, "This reminds me of my grandmother's garden." It is an acquired taste.) Edit: and kombucha, which is fermented after being steeped, rather than before. Also by many accounts an acquired taste.
The term black tea is ambiguous because it refers to different things depending on where you are/who you are talking to. In the west, black tea generally refers to a fully oxidized (autolysis) red tea that has not been fermented. However, in other parts of the world black tea refers to fermented puerh. How the puerh is fermented depends on whether it is wet or dry processed (shu vs sheng) but fermentation is an important part of both processes.
That's a very good description of the enzymatic process in tea.
Regarding "oldest process" though, I'm not sure which is the earliest processing method for tea but compressed tea / tea bricks as Pu-erh (although compressed tea ≠ Pu-erh) is attributed to Tang dynasty (AD 618-907) and it precedes Matcha which is attributed to the Song dynasty period (960–1279).
The problem with summarizing complex things for people is that you leave out the bits that you don't think will stick, and even what is left over becomes a game of telephone.
At the time, puehr was about to have a little resurgence but was pretty obscure in the west. I'm not sure which of us redacted that from the brief timeline.
I like a little puehr once in a while. It tastes like leaf mould smells, which is probably not far off from reality.
Edit: some imported tea is still delivered in compressed bricks, green, black and oolong. Among those are teas that are treated like scotch. and I have seen but not tasted a 25 year old tea brick (which I think she kept in part for bragging rights. IIRC it was not for sale.) I already have a Scotch habit, I don't need to be buying 18 year old tea on top of it, so as curious as I was I made no attempts to get involved in any private tea tastings.
Agreed. AFAIK it was created as a method to transport tea efficiently all across the Tang empire (and as a mean to keep the peace within it) while not crushing the leaves. I have no idea about what kind of tea made it to the west back then.
Even today most western people aren't aware of the variety of teas there are out there or how wildly different the final product is depending on the processing methods, let alone bush cultivar, age, flush stage, altitude etc.
Pu-erh really can be weird, Hei-Cha even weirder I think. It took my quite a while to like pu-erh and if it wasn't for its aesthetics I'm not sure I'd have bothered to try that much. For my palate, Shou pu-erh teas were an easier taste to acquire. It took me a lot of trial and error to get my palate around Shengs but now I like it well enough to get the same kind of craving I get for a good coffee.
I'm on the same boat now, it was a hard start because I tried young shengs first and didn't know what notes to look in them. After trying some affordable aged CNNPs (from YS), I found my liking to younger shengs too.
Nice to see there's a sub-community of tea lovers here on HN.
The way they drank tea in the Han dynasty is interesting; centuries before before a real processing method came about.
Guo Pu noted in the book Er Ya (Chinese: 尔雅), the earliest Chinese dictionary, tea can be boiled to consume like thick soup. More precisely, to make a cup of tea at that time you need to mix millet and other condiments with tea leaves first them boil them together till mushy state
I've heard that in Tang dynasty Pu-Erh was important in order to keep the peace in remote areas partially because it was consumed as a substitute for fresh vegetables in areas where one could not grow them.
Consuming tea as thick soup to me suggests the idea that maybe tea was used in that way even back in Han dynasty (I'm sure that whether this is correct or not would be obvious to a historian, which I'm not).
Do you have any recommendations for a curriculum of sort for tea history?
I love pu erh tea! Though I worry about good sources of it. Brew-wise you can brew it very long and at high temperatures and it’ll be stronger, but not necessarily ruined. I can understand calling it an acquired taste, but it probably comes the closest to fulfilling a similar coffee taste of the teas.
You sure on the oxalic acid aspect? I could see it maybe for bugs, but I figured the crystals would be too tiny. Oxalic acid causes kidney problems in larger organisms because it is hard to process. I suppose its crystal formation and poor solubility are linked here.
I was sort of suffering from colored tooths (teeth?) problem. Meaning every time I took selfie I suffered about 5 seconds. The bloody dentist suggested monthly visits to the bloody dental hygienists.
Strange thing happened: I was flying my kite for kite aerial photography and a chinese ((or taiwanese) or japanese) tourist noted my blackened teeth an told that green tea does not color. And it worked ok. Even the cheapest Lidl tea works ok. I bit of acquired taste, but you will learn to love it.
I actually prefer green tea and would urge you to try some "good" ones instead of the Lidl one :)
The difference is huge if you have a high quality green tea. Also make sure to use the right temperature to infuse. I would never go higher than 80°C and for some teas I only us 70°C. This is the most important thing a lot of people do wrong. Hotter water destroys the flavor and makes the tea bitter. Also very short steeping times from 1m to 1,5m are the norm.
Another thing noteworthy is that you can actually use a portion of green tea for 2-3 times depending on the quality (on the same day).
I'd like to try this but it seems just about impossible to locate actual high quality green tea online.
Basically every green tea product on amazon, even those in the price range of $50 for a standard quantity, has loads of reviews talking both about how excellent it is and how terrible it is, each bringing detailed points in their favor.
I figure it's mostly due to review warfare between products, but in any case the situation is quite dismal—I investigated something like 30 products and couldn't find a single one that looked like a safe purchase, even with a very flexible budget.
Not sure where else to look since the same problem exists on a larger scale with the rest of the internet since everyone's trying to push their brand or trash someone else's.
Not sure where you are located but e.g. here in Germany there are quite a few online tea merchants where you can buy good tea. I would never try to find tea on Amazon or ebay.
Aside from the online merchants you can find small tea shops in all cities usually.
And aside from the quality the taste preferences vary a lot obviously. Most tea shops offer some set/package with a lot of different teas in small quantities for testing.
> I was flying my kite for kite aerial photography and a chinese ((or taiwanese) or japanese) tourist noted my blackened teeth an told that green tea does not color. And it worked ok.
I think black (red) tea is very much worth it. I just couldn't do without at least a single cup a day. I do brush my teeth afterwards though.
Traditionally white tea was created from tea buds. If you've ever gardened, you know how dicey those first few days are because the plants that have defenses against caterpillars and slugs are vulnerable until the leaves are fully formed. Caffeine is a pesticide, and the young shoots don't contain much of it. Last I remembered looking, white tea has about the same caffeine as decaffeinated coffee (which I use both as a sales pitch for getting people to try white tea and a warning against people complaining about having trouble sleeping - there's still caffeine in your decaf, buddy).
Since you pick the leaves before they are grown, you're pruning the tree and potentially reducing your crop. Which is why it was a drink of the nobility. Basically you're so rich you can afford to reduce your crop by (conjecture) 10% for a taste sensation, or pay someone else for the privilege.
I suspect we have so much of it now because 1) Republic of Tea basically went through every tea fad in the history of tea in a 15 year period, presumably to keep sales numbers up with novelty, and 2) it's likely that there is oversupply in the tea market, so white tea gives you another shot at a sale.
Unlike coffee, which gets one harvest per year (although some people are trying to bring coffee leaf tea into the group consciousness), it's typical to get at least 2 harvests of tea per year, 3 or more in a great year. Which I discovered when I noticed my dealer putting numbers and/or seasons on her tea. If they are regrowing that fast then white tea might not be that big of a burden.
That would be green tea no? You pick the green tea, cook it to denature the enzymes to arrest the oxidization (called the "killgreen" step in Chinese) and voila, green tea! Lots of green teas can be quite smooth and even more so with more careful brewing.
The Brit I mentioned elsewhere seemed to think it was the drying that arrested the chemical processes in the tea.
He was also adamant about storing it in well sealed containers out of direct sunlight. I ended up throwing away a couple of containers because of this (although I've kept a couple that are just too beautiful to part with - I store my daily drinker in there since it doesn't need to keep as long). Also explains why my dealer uses mylar vacuum packs for anything over an ounce. No oxygen, no light.
White tea does not undergo the "killgreen" step that green teas and oolongs teas do IIRC. The drying slows the oxidation but does not arrest it. "Aged" white tea is a thing. If you let it sit around long enough it turns deep red. Green tea just turns into stale tea. They even compress white teas into something similar to those "Pu'er Cakes".
Yes, green tea needs lower temperature and controlled infusion time, but rewards that. The author definitely does not seem to be a fan and is not doing it justice.
Yeah! Green tea gets fried or steamed right away to halt oxidation. That kills off some of the undesirable bitterness that masks some flavors that are even present in fresh leaves. It is not that Green doesn’t have any taste; it is that there are more guardrails over what flavors can appear and how distinct they can be.
The odd thing is that the range (and top end) of antioxidants in white tea is larger than in green.
"Total catechin content (TCC) for white teas ranged widely from 14.40 to 369.60 mg/g of dry plant material for water extracts and 47.16 to 163.94 mg/g for methanol extracts. TCC for green teas also ranged more than 10-fold, from 21.38 to 228.20 mg/g of dry plant material for water extracts and 32.23 to 141.24 mg/g for methanol extracts."
May just be the prices on their website, but they strike me as being quite expensive. They also use anglicized names with very little information about the tea, so it's hard to know what you're buying.
yeah it's definitely expensive but that's mainly because they go to China every year to each farm to find the best teas. they will go into depth on each and every one if you inquire
How about manipulating Oxidation of your tea cup? I add a squeeze of lemon and the tea lightens up in color, and it lasts longer before it tastes stale. In addition to lemon, I would add either cardamom,or cinnamon, or event mint leaves, and the over-oxidation that would make my cup of tea go stale will be delayed. I am that lazy tea drinker who is OD'ing on tea/j.
"Contrary to popular belief, Red teas like Darjeeling actually have less caffeine than White or Green teas because they are so highly processed."
Is this actually true? I've never heard of green tea having more caffeine than red tea, besides maybe gunpowder green tea, which retains more caffeine due to less breakage from being rolled up.
A while back I looked at a few chemistry papers on measuring caffeine content in a variety of tea leaves, in the hopes of finding some low-caffeine green/oolong I could drink late at night. The impression I got was that there is so much variation batch to batch or year to year (not to mention preparation) that it largely swamps any attempt to say 'Darjeeling has less caffeine than Gunpowder Green'. There may be average differences but it's not too useful to know. Whether Red or Green, that tea could still easily be one that will keep you up if you drink it at 10PM. Ah well. (And decaffeinated teas are uniformly garbage-tasting, so that's no, ahem, solution.)
I think lighter teas does have more caffeine per weight, but they're have much shorter infusion times (with the exception of Pu'er, which can go through15 infusions).
I think it's some of both. I emulate my dealer (Taiwanese direct importer), who intimated that she skips the strainer with her green tea and just puts here whole leaf green tea straight into the cup (you can only do this with whole leaf, as your lip becomes the strainer and broken tea ends up in your teeth). She reuses the same cup all day, topping it off when it's half full. When I space and drain it (often in the middle of a coding session), it still tastes and acts like tea for at least the first three cups, after that it gets pretty weak, until I abandon it for a good long while and then discover it's gone from weak to bitter.
Ah that would make sense. And water temperature likely plays a vital role as well. But for properly brewed green tea, it will still result in less caffeine than red tea as expected.
I'm not sure it's so much removing as bioavailability. As I just stated up thread, black and green tea rely on autolysis - enzymes in the leaf decompose insoluble caffeine crystals into a water soluble form.
L theanine I think may be some of both. The heating and drying processes also help define what kind of tea you get, and we know that some vitamins don't survive cooking all that well (famously, sailors and scurvy).
My suspicion here is that black tea, especially when prepared in the British style, has more caffeine per cup because it's brewed to be much stronger than green teas typically are. So both can be true, black tea typically has more caffeine per cup, but black tea leaves have less caffeine than green tea leaves when compared by weight or volume.
Red tea from Darjeeling is in a category called CTC tea, which is distinct from what you'd expect from black tea. Easy mixup since they look similar, besides the packaging
Generalizations like this are always dicey, especially when the statements are so imprecise. Is he talking about green tea vs black tea leafs, or prepared green vs black tea? When he says green tea, what variety?
Higher weight polyphenols tend to taste less bitter than lower weight ones. Its more correlation than causation because I don’t think we precisely know why this is.
I wonder if they're talking about the blurred lines between taste and smell. Most of what we 'taste' is happening in our nose.
Turns out the French and Italians with all of their fancy wine glasses for different kinds of wine are not insane. Glass shape effects the timing of scent versus taste, and so lighter wines have a narrower glass to shorten the time. The heavier the red the wider the glass.
An interesting colour change I've noticed it when you squeeze lemon into dark (almost black) tea. It lightens up a lot and becomes a pale brown. I'm not sure what but there is some chemical change going on there.
“The thearubigins in brewed tea are highly coloured (red-brown) molecules that change according to the acidity of the liquid used.
If the water used for the tea infusion is relatively alkaline (for example, due to limescale found in “hard” water), the colour of the tea will be darker and deeper.
However, once an acid such as a slice of lemon or lemon juice is added, tea changes colour because of an increase in acidity (reduction in pH) of the beverage itself. Lemon juice is quite strong as a food acid – a few drops are enough to alter the theaurbigins, resulting in a dramatic change in colour. Interestingly, theaflavins are not that affected by the change in acidity, and still retain their normal dark red colour.”
This is a pretty thorough intro to (mostly) Chinese tea, which seems fair to me since tea originated in China. Though I can see a few details to quibble over (e.g., some Taiwanese oolongs are barely oxidized, ~5% for Baozhongs sometimes[1]). Personally as much as I like white, green, and black teas, I think oolongs have the most variation, since they can have a mix of the characteristics of the other types. But I drink plenty of them all.
The other dark tea, the fermented tea they mention in this article aka hei cha or commonly referred to as pu’er, scares me because there are bad quality versions of it containing mold due to their fermentation process. Hard to detect since it’s also a kind of black tea.
It's not a black tea, at least in the western sense. Our black tea is actually called hong cha in Chinese, which means red tea. They're simply different types of tea.
There are also two different style pf pu'ers which have little to do with each other. The style you're talking about is shu pu'er, which is deliberately piled and made wet in order to trigger a sped up fermentation process. This is opposed to sheng pu'er, which is processed into bricks from very young, raw leaves called maocha, and is then aged for a number of years before it is drank. This results in a much slower and subtler fermentation process. The taste of shu and sheng are quite different.
I've never personally had an encounter with a bad batch of either shu or sheng pu'er, but the shu variant is more prone to this due to the process.
It's notable that pu'er is steeped at a (close to) 100 degrees celsius and the first one or two short steepings are discarded. This is to kill and wash off any microorganisms or dirt that may be present.
Puerh is not heicha. Puerh comes in two varieties, only one of which commonly counts as heicha. Heicha is a variety of tea preparation styles that involves post-processing fermentation. This also includes Eg. Fu bricks or liubao.
Tulsi, aka holy basil, has a lot of effects, but not really psychoactive ones. It’s generally thought to have a wide range of beneficial properties on stress, the immune system, etc but it does disagree with some people too.
There were a bunch of charts about time and temperature and humidity for various types of tea but the biggest fact was slightly buried. 'fermentation' with respect to tea is a bit of a euphemism. It's actually autolysis. The big epiphany moment for me was connecting the dots and seeing why that was the case. Caffeine is an insecticide. It's stored in little crystals in the tissue. With oxalic acid, the crystals are the point. They're sharp and they damage the attacker.
With caffeine it's metabolic disruption. Within other organelles in the tea leaf are enzymes that can decompose the caffeine crystals into a solluble form. These chemicals only mix when the leaf is bruised, or masticated. They are booby trapped.
When you process camellia sinensis into tea, the oldest process is matcha, which started in China and is now mostly preserved in Japan, is drying the leaves and then powdering them, which I presume frees up some of the caffeine simply by mechanical decomposition. For the others the leaves are processed by bruising, heating and drying the leaves, and the order and duration dictates which kind of tea you get, and how much of the caffeine has been converted to a form that is water soluble. Black tea is aged longer, and has more available caffeine.
Almost none of them are actually fermented as in beer (puehr is the most notable, and the common reaction upon smelling it is, "This reminds me of my grandmother's garden." It is an acquired taste.) Edit: and kombucha, which is fermented after being steeped, rather than before. Also by many accounts an acquired taste.