4 ms·

Tea Chemistry (1997)

83 points by aabiji 8mo ago

wolfi1 8mo ago
quite interesting but I would have expected some insight into the preparation itself as how long do you have to steep, what temperature should the water have, etc
- n4r9 8mo ago
  I'm not sure there's much real scientific research on preparation (at least when this was published in the 90s), especially as it can be quite subjective. There's a bit about factors affecting caffeine content on p.425: > The quantity of caffeine that infuses into a tea brew is determined by infusion time and by leaf style. Longer infusion times lead to greater quantities of caffeine in a tea beverage. Smaller sized tea leaves give a more rapid and stronger infusion, whereas larger leaves and uncut leaves lead to weaker infusions. This results in more or less caffeine extraction, respectively. The caffeine content of a typical tea beverage will range from 20 to 70 mg per 170 ml of infusion, with a typical infusion being prepared from about 2 to 2.5 g of tea leaves. Coffee brews typically contain from 40 to 155 mg caffeine per 170 ml beverage. There has been little research done on the pharmacology of tea-beverage caffeine. One study suggests a dose of caffeine from tea has a different physiological effect than a pure dose of caffeine (Das et al., 1965). This has been attributed to the amino acid theanine, which is unique to tea. However, there are no well-designed clinical studies to support this position. The consensus among scientists today is that caffeine from all beverage sources has a similar physiological effect. The actual content of caffeine depends on many factors, particularly the method of brewing. A brew prepared by the Chinese "gong-fu" style is likely to have a different caffeine impact compared with the Western style of loose tea or to that from a tea bag (Hicks et al., 1996). Some reports have suggested that green tea contains significantly less caffeine than black tea. This may be influenced by the clone of leaf used to produce the tea or by the impact of different brewing techniques. No significant differences have been found when brewing green and black teas under similar conditions (Hicks et al., 1996), discrediting the theory that withering and fermentation have a significant impact on caffeine content (Sanderson, 1972).
- tmtvl 8mo ago
  Well, depending on what you drink there are articles about that: https://news.ycombinator.com/item?id=35658412 https://news.ycombinator.com/item?id=35658412
- teleforce 8mo ago
  The BBC has come up with an excellent short documentary on how to perform proper tea preparation [1]. Essentially the hot water need to be boiling hot (100 degree celcius) and leave it brewing for a minimum 4 minutes after pouring into a cup of tea. From personal experiences, if you want to make good chai masala (or spicy milk tea) you need to keep it in boiling water for considerable amount of time (like cooking on stove), with the ingredient of tea (generous amount), equivalent amount of evaporated and sweetened condensed milk (like half can of milk for medium pot), together with combination of your preferred different spices for examples cinnamon (Sri Lanka cinnamon not the fake ones), jeera, clove, star anise, etc. Since the condensed milk is already sweetened, no need to put sugar, but you can add pure honey for extra wonderful aftertaste. In UAE, karak chai is their national drink that are sold in most of the restaurants and eateries. Fun facts, and heaven knows for whatever reason the default tea brand being used there is always Lipton. [1] How you've been making tea WRONG your entire life - BBC: https://youtu.be/Fhuc6qOGNPc https://youtu.be/Fhuc6qOGNPc
  - card_zero 8mo ago
    (Jeera == cumin. "Fake cinnamon" I guess comes from species in the genus Cinnamomum other than the Sri Lanka / Ceylon species.)
    - t-3 8mo ago
      Mainly just avoid Chinese cinnamon/cassia, as it has a more complex bitter flavor (good for savory, not so much for sweet).
  - xattt 8mo ago
    Science has shifted, depending on the discipline, from a colonial universalism perspective to one that accepts that “the truth” varies and can be a local phenomenon. I have a hard time buying into a prescriptive tea-making procedure. For example, you can heat up your temperature to boiling, but by the time you pour it, it will likely be down to the low to mid 90s. There’s other factors such as the material of the mugs (which might be more or less conductive of temperature) and the delta between the water and air temps. The composition of the tea itself will also vary year-to-year and you have no idea of the vintage of the Lipton/Tetley tea bag dust stock you’re buying. tl;dr Strict procedure = placebo
- gilrain 8mo ago
  It depends on the tea you’re brewing, what you want to make with it, and your personal taste. How could there possibly be an objective answer?
  - IAmBroom 8mo ago
    Perhaps not, but there are very objective, erm, pathways. Want to avoid dissolving the more bitter flavor components? Steep at a lower temperature. Solubility curves are quasi-exponential with temperature, and a reduction from 95 to 85 C can spread out the time before tannins are strongly dissolved. You could get the exact same flavor at 95, perhaps, if you used a stopwatch. But objectively, the tea will get much more bitter a few seconds later. Objective lesson: to allow for ease in steeping timing, use a lower temperature. It's especially true for green teas, which (objectively) have more bittering compounds than fermented teas. But: many Chinese people enjoy their green teas at a saturation (color) that I would call barely-not-water. Many Brits enjoy black breakfast teas brewed to levels I would only use to dye cloth. Plenty of subjectivity.
the-mitr 8mo ago
of possible interest George Orwell's 11 rules of tea making https://www.orwellfoundation.com/the-orwell-foundation/orwell/essays-and-other-works/a-nice-cup-of-tea/ https://www.orwellfoundation.com/the-orwell-foundation/orwel...
- ghtbircshotbe 8mo ago
  6 heaping teaspoons of tea per quart of water seems like a lot of tea.
  - fransje26 8mo ago
    It depends on how much you want to sleep in the coming days..
    - iberator 8mo ago
      You must be from USA. In Europe you give tea even to toddlers and they sleep just fine. You mistook tea for coffee lol (Americans...)
      - t-3 8mo ago
        Coffee usually has about twice as much caffeine per cup as tea, but that depends a lot on the variety of tea and the brewing method/amount used.
      - Foobar8568 8mo ago
        Europeans have a tendency to not make the distinction between herbal infusion and tea... No one is giving tea to toddlers, well I hope not.
        IAmBroom 8mo ago
        Americans in the last century advocated giving whiskey to teething infants. Your pearls are adequately clutched, but I guarantee someone somewhere has given "the devil brew" to innocent babes.
pasc1878 8mo ago
Experiments on how to make tea (well does milk go in before or after) is the original exposition of statistical testing of the null hypothesis. https://en.wikipedia.org/wiki/Lady_tasting_tea https://en.wikipedia.org/wiki/Lady_tasting_tea
blacksmith_tb 8mo ago
Worth mentioning that though tea does contain polyphenols and flavinoids which are good for us (and l-theanine and caffeine which we enjoy introducing to our nervous systems), it's had a much bigger impact on health historically because it required us to heat water to boiling (or near boiling, depending on what kind of tea you're making). Also, can't miss a chance to spice things up with the mention of adding salt to brewed tea[1]. Which is heretical, but seems palatable to me, though I probably wouldn't do it to good tea. 1: https://www.bbc.com/news/uk-68085304 https://www.bbc.com/news/uk-68085304
- wallygator88 8mo ago
  Salted black tea with butter is delicious (https://simplytibetan.com/2010/12/07/bho-ja/ https://simplytibetan.com/2010/12/07/bho-ja/)
- MisterTea 8mo ago
  When I switched to black coffee I read that putting a tiny bit of salt in cuts the bitterness. It works and the amount of salt needed is so small that you don't taste it, less than a pinch.
  - IAmBroom 8mo ago
    Likewise, it enhances things like smoothies, martinis, and damn near anything with bitterness or sweetness in their profiles, generally added at levels that are not perceptible as "salty".
jfil 8mo ago
You can brew your tea extremely strong, and get a hallucinogenic prisoner's drink called "Chifir"

83 points by aabiji 8mo ago

quite interesting but I would have expected some insight into the preparation itself as how long do you have to steep, what temperature should the water have, etc

n4r9 8mo ago
I'm not sure there's much real scientific research on preparation (at least when this was published in the 90s), especially as it can be quite subjective. There's a bit about factors affecting caffeine content on p.425: > The quantity of caffeine that infuses into a tea brew is determined by infusion time and by leaf style. Longer infusion times lead to greater quantities of caffeine in a tea beverage. Smaller sized tea leaves give a more rapid and stronger infusion, whereas larger leaves and uncut leaves lead to weaker infusions. This results in more or less caffeine extraction, respectively. The caffeine content of a typical tea beverage will range from 20 to 70 mg per 170 ml of infusion, with a typical infusion being prepared from about 2 to 2.5 g of tea leaves. Coffee brews typically contain from 40 to 155 mg caffeine per 170 ml beverage. There has been little research done on the pharmacology of tea-beverage caffeine. One study suggests a dose of caffeine from tea has a different physiological effect than a pure dose of caffeine (Das et al., 1965). This has been attributed to the amino acid theanine, which is unique to tea. However, there are no well-designed clinical studies to support this position. The consensus among scientists today is that caffeine from all beverage sources has a similar physiological effect. The actual content of caffeine depends on many factors, particularly the method of brewing. A brew prepared by the Chinese "gong-fu" style is likely to have a different caffeine impact compared with the Western style of loose tea or to that from a tea bag (Hicks et al., 1996). Some reports have suggested that green tea contains significantly less caffeine than black tea. This may be influenced by the clone of leaf used to produce the tea or by the impact of different brewing techniques. No significant differences have been found when brewing green and black teas under similar conditions (Hicks et al., 1996), discrediting the theory that withering and fermentation have a significant impact on caffeine content (Sanderson, 1972).
tmtvl 8mo ago
Well, depending on what you drink there are articles about that: https://news.ycombinator.com/item?id=35658412 https://news.ycombinator.com/item?id=35658412
teleforce 8mo ago
The BBC has come up with an excellent short documentary on how to perform proper tea preparation [1]. Essentially the hot water need to be boiling hot (100 degree celcius) and leave it brewing for a minimum 4 minutes after pouring into a cup of tea. From personal experiences, if you want to make good chai masala (or spicy milk tea) you need to keep it in boiling water for considerable amount of time (like cooking on stove), with the ingredient of tea (generous amount), equivalent amount of evaporated and sweetened condensed milk (like half can of milk for medium pot), together with combination of your preferred different spices for examples cinnamon (Sri Lanka cinnamon not the fake ones), jeera, clove, star anise, etc. Since the condensed milk is already sweetened, no need to put sugar, but you can add pure honey for extra wonderful aftertaste. In UAE, karak chai is their national drink that are sold in most of the restaurants and eateries. Fun facts, and heaven knows for whatever reason the default tea brand being used there is always Lipton. [1] How you've been making tea WRONG your entire life - BBC: https://youtu.be/Fhuc6qOGNPc https://youtu.be/Fhuc6qOGNPc
- card_zero 8mo ago
  (Jeera == cumin. "Fake cinnamon" I guess comes from species in the genus Cinnamomum other than the Sri Lanka / Ceylon species.)
  - t-3 8mo ago
    Mainly just avoid Chinese cinnamon/cassia, as it has a more complex bitter flavor (good for savory, not so much for sweet).
- xattt 8mo ago
  Science has shifted, depending on the discipline, from a colonial universalism perspective to one that accepts that “the truth” varies and can be a local phenomenon. I have a hard time buying into a prescriptive tea-making procedure. For example, you can heat up your temperature to boiling, but by the time you pour it, it will likely be down to the low to mid 90s. There’s other factors such as the material of the mugs (which might be more or less conductive of temperature) and the delta between the water and air temps. The composition of the tea itself will also vary year-to-year and you have no idea of the vintage of the Lipton/Tetley tea bag dust stock you’re buying. tl;dr Strict procedure = placebo
gilrain 8mo ago
It depends on the tea you’re brewing, what you want to make with it, and your personal taste. How could there possibly be an objective answer?
- IAmBroom 8mo ago
  Perhaps not, but there are very objective, erm, pathways. Want to avoid dissolving the more bitter flavor components? Steep at a lower temperature. Solubility curves are quasi-exponential with temperature, and a reduction from 95 to 85 C can spread out the time before tannins are strongly dissolved. You could get the exact same flavor at 95, perhaps, if you used a stopwatch. But objectively, the tea will get much more bitter a few seconds later. Objective lesson: to allow for ease in steeping timing, use a lower temperature. It's especially true for green teas, which (objectively) have more bittering compounds than fermented teas. But: many Chinese people enjoy their green teas at a saturation (color) that I would call barely-not-water. Many Brits enjoy black breakfast teas brewed to levels I would only use to dye cloth. Plenty of subjectivity.

the-mitr 8mo ago

of possible interest George Orwell's 11 rules of tea making https://www.orwellfoundation.com/the-orwell-foundation/orwell/essays-and-other-works/a-nice-cup-of-tea/ https://www.orwellfoundation.com/the-orwell-foundation/orwel...

ghtbircshotbe 8mo ago
6 heaping teaspoons of tea per quart of water seems like a lot of tea.
- fransje26 8mo ago
  It depends on how much you want to sleep in the coming days..
  - iberator 8mo ago
    You must be from USA. In Europe you give tea even to toddlers and they sleep just fine. You mistook tea for coffee lol (Americans...)
    - t-3 8mo ago
      Coffee usually has about twice as much caffeine per cup as tea, but that depends a lot on the variety of tea and the brewing method/amount used.
    - Foobar8568 8mo ago
      Europeans have a tendency to not make the distinction between herbal infusion and tea... No one is giving tea to toddlers, well I hope not.
      - IAmBroom 8mo ago
        Americans in the last century advocated giving whiskey to teething infants. Your pearls are adequately clutched, but I guarantee someone somewhere has given "the devil brew" to innocent babes.

pasc1878 8mo ago

Experiments on how to make tea (well does milk go in before or after) is the original exposition of statistical testing of the null hypothesis. https://en.wikipedia.org/wiki/Lady_tasting_tea https://en.wikipedia.org/wiki/Lady_tasting_tea

blacksmith_tb 8mo ago

Worth mentioning that though tea does contain polyphenols and flavinoids which are good for us (and l-theanine and caffeine which we enjoy introducing to our nervous systems), it's had a much bigger impact on health historically because it required us to heat water to boiling (or near boiling, depending on what kind of tea you're making). Also, can't miss a chance to spice things up with the mention of adding salt to brewed tea[1]. Which is heretical, but seems palatable to me, though I probably wouldn't do it to good tea. 1: https://www.bbc.com/news/uk-68085304 https://www.bbc.com/news/uk-68085304

wallygator88 8mo ago
Salted black tea with butter is delicious (https://simplytibetan.com/2010/12/07/bho-ja/ https://simplytibetan.com/2010/12/07/bho-ja/)
MisterTea 8mo ago
When I switched to black coffee I read that putting a tiny bit of salt in cuts the bitterness. It works and the amount of salt needed is so small that you don't taste it, less than a pinch.
- IAmBroom 8mo ago
  Likewise, it enhances things like smoothies, martinis, and damn near anything with bitterness or sweetness in their profiles, generally added at levels that are not perceptible as "salty".

jfil 8mo ago

You can brew your tea extremely strong, and get a hallucinogenic prisoner's drink called "Chifir"