In the old times, when people made tea, we can be almost certain that no one would have thermometers or the like at their disposal.
Not even mentioning that it would probably ruin the concept of a tranquil Japaneses tea ceremony… Myself that is the very reason I also do not use any tool as such, apart from wanting to keep things simple and in order not to over-think it.
But – especially for the aforementioned Japanese way of tea, water temperature is of the essence as to not ruin the tea. So how did they and other tea-cultures control this factor?
The one method most know is watching the bubbles in the kettles to determine an approximate temperature, crab eyes, fish eyes etc.
But then once out of the kettle, what then?
I imagine that the pure length of the procedural length of the Chado is probably enough to make sure that the water is not too hot.
Personally, I have used the method of transferring water from the kettle to a pitcher first, which has been usually enough to get the temp down to the level I needed it. Other methods consist of how to pour and where the water hits the brewing vessel.
I remember from a Japan trip, seeing a rather elaborate number of change of vessels, before the tea reached the cup. As well as a rotating motion with the water holding pitcher, I imagine in order to decrease temperature.
Thoughts? Historical/anecdotical knowledge anyone?
I think it could be interesting to investigate how things where done in the old days to improve our present day brewing methods.
Thanks everyone!
Traditional Methods of Estimating Water Temperature
For those who are not familiar with the Chinese method of determining the water temperature by observation, here is a good summary:
https://www.goldenmoontea.com/blogs/tea ... em-for-tea (no affiliation with that site, came about it randomly)
Shrimp eyes > crab eyes > fish eyes > rope of pearls > raging torrent
However, I found that this method does not work with all kettles. It worked on my clay kettles, yet for some reason does not with my tetsubin. I also used to be able to know the rough temp, by listening to my clay kettle. Takes some observing to figure out one's individual kettle's stages of noise during heating.
External factors can influence the above as well, like room temp and humidity.
https://www.goldenmoontea.com/blogs/tea ... em-for-tea (no affiliation with that site, came about it randomly)
Shrimp eyes > crab eyes > fish eyes > rope of pearls > raging torrent
However, I found that this method does not work with all kettles. It worked on my clay kettles, yet for some reason does not with my tetsubin. I also used to be able to know the rough temp, by listening to my clay kettle. Takes some observing to figure out one's individual kettle's stages of noise during heating.
External factors can influence the above as well, like room temp and humidity.
Great topic Bok. Last year a few reps from Kagoshima visited me with some of their teas to share. I of course am so used to my variable temperature kettle that I offered to set the correct temperature for them. The reply was just under boil, it was a good reminder to see how easily they estimated correct temperature for the Japanese green teas they brought with; get water to almost boil, fill kyusu, transfer to 5 cups, transfer to yuzamashi (water cooler), and back into kyusu that now has tea leaves warmed and waiting full of aroma. During each transfer there is a time interval with a pause further cooling water. I estimated each transfer cools water down +-20F. So if you start with 205F you end up with +-145F depending on vessels used and length of pause between transfers.
I think with a narrow enough window of tea varieties used, for a long enough period of time, it becomes second nature to estimate both temperature and steeping time. Since participating in tea tastings here with a variety of different teas from pu’erh, black, white, green, oolong, I seem to have become a horizontal explorer, making this kind of narrower precision more difficult. I do though still preheat kyusu and cups when the temperature needs to get below 140F. With oolong though it’s much easier, rope of pearls and pour into preheated pot with warming aromatic leaves.
Adding a link to a related topic: Looking for Yuzamashi info
I think with a narrow enough window of tea varieties used, for a long enough period of time, it becomes second nature to estimate both temperature and steeping time. Since participating in tea tastings here with a variety of different teas from pu’erh, black, white, green, oolong, I seem to have become a horizontal explorer, making this kind of narrower precision more difficult. I do though still preheat kyusu and cups when the temperature needs to get below 140F. With oolong though it’s much easier, rope of pearls and pour into preheated pot with warming aromatic leaves.
Adding a link to a related topic: Looking for Yuzamashi info
A long time ago when i was starting to explore teas and played with greens, i'd just use my finger: depending on how quickly it would start to feel uncomfortably hot would give a pretty good idea of the temperature. Now i just use either "hot" or "as hot as possible" water for everything. 
I use sound to clue me in on the temp but it requires a lot of time getting familiar with the sound a kettle makes at different temperatures. Of course, it also means having a thermometer in the kettle until the sounds are learned. I like using sound because I don’t have to lift the lid and lose heat.
This works best, in my opinion, with stainless steel kettles. I am still trying to pin down the sounds of my clay kettle, made difficult because it is made from a thick clay that muffles the sound.
For most Japanese green teas I pour the water between cups and/or yuzamashi until the water is cool enough. I used a thermometer to guide me at first but it was easy to determine that there was approximately a 10°F drop per transfer.
Regarding how they did it in the old days, it is important to remember that teas appear to have been more forgiving of heat than the teas we enjoy today. This can be seen with zairai, which has virtually no bitterness to it and was historically boiled not steeped. Zairai was seed grown and each bush was genetically different from every other bush in the harvest. As best as I can tell zairai and the sencha of antiquity are virtually the same in terms of genetic diversity and lack of bitterness.
One of the caveats of producing tea varietals with novel aromas is that these varietals are more susceptible to bitter elements, especially with the inclusion of Assam genetics. In Japanese teas, many of these are inzatsu, that is, varietals made by crossing with Assams.
I digress, but my point is that tea temperature appears to matter more with modern teas than seed-grown Camilla sinensis-sinensis that were not crossed with Assams. Cloning was certainly known for hundreds of years but the bitterness that we take such care to avoid with proper heat, in my experience, was introduced with Assam genetics in the past 70-80 years.
This works best, in my opinion, with stainless steel kettles. I am still trying to pin down the sounds of my clay kettle, made difficult because it is made from a thick clay that muffles the sound.
For most Japanese green teas I pour the water between cups and/or yuzamashi until the water is cool enough. I used a thermometer to guide me at first but it was easy to determine that there was approximately a 10°F drop per transfer.
Regarding how they did it in the old days, it is important to remember that teas appear to have been more forgiving of heat than the teas we enjoy today. This can be seen with zairai, which has virtually no bitterness to it and was historically boiled not steeped. Zairai was seed grown and each bush was genetically different from every other bush in the harvest. As best as I can tell zairai and the sencha of antiquity are virtually the same in terms of genetic diversity and lack of bitterness.
One of the caveats of producing tea varietals with novel aromas is that these varietals are more susceptible to bitter elements, especially with the inclusion of Assam genetics. In Japanese teas, many of these are inzatsu, that is, varietals made by crossing with Assams.
I digress, but my point is that tea temperature appears to matter more with modern teas than seed-grown Camilla sinensis-sinensis that were not crossed with Assams. Cloning was certainly known for hundreds of years but the bitterness that we take such care to avoid with proper heat, in my experience, was introduced with Assam genetics in the past 70-80 years.
Last edited by Baisao on Fri Sep 20, 2019 1:40 am, edited 1 time in total.
My way of temperature estimation is a combination of what have already been said here.
I know when the water is pre-boiling with the sound (crab-eyes bubbles) then I set the kettle heater on low heat in order to maintain it juste boiling in the case I use it straight away for teas that need boiling water.
When brewing sencha I take the kettle off the heater and use the method Victoria describe above, pouring in the kyusu, cups, pitcher and back in the kyusu where I did put leaves when pre-heated. For the next infusion I only pour in the pitcher and then in the kyusu. Finally, I pour directly in the kyusu from the kettle for a 3rd brew. This makes the temperature increase about 5C per brewing. If I want to continue, I need to re-heat the kettle a little, back to crab-eyes bubbles.
I know when the water is pre-boiling with the sound (crab-eyes bubbles) then I set the kettle heater on low heat in order to maintain it juste boiling in the case I use it straight away for teas that need boiling water.
When brewing sencha I take the kettle off the heater and use the method Victoria describe above, pouring in the kyusu, cups, pitcher and back in the kyusu where I did put leaves when pre-heated. For the next infusion I only pour in the pitcher and then in the kyusu. Finally, I pour directly in the kyusu from the kettle for a 3rd brew. This makes the temperature increase about 5C per brewing. If I want to continue, I need to re-heat the kettle a little, back to crab-eyes bubbles.