Great find, @Tor!
It’s not bad tea by any means but it does taste different than conventionally made sencha, which is more savory and viscous.
I had a kama-iri made from yabukita cultivar made essentially in the “less leaves way” and it was good. This was prepared by a friend who runs a tea shop during a private tasting. I got a lot of the strange characteristics of that tea I lovingly nicknamed Sasquatch because it had such a pronounced animal aroma during the tasting. I then made it at home the conventional way and the elements of the animal smell became more separated: kombu dashi, smoked peat, salt, broiled scallops. I‘ve wondered where that animal smell went but now I think you’ve helped answer this minor riddle.
Sencha: what water temp do you use for the second cup?
But gong fu uses more leaves not less, as in this hot temp technique. I think the solution is dilution for why it works for Japanese teas.Bok wrote: ↑Sat Jan 25, 2020 2:31 amThat backs up my own experiences, if the quality is good enough very hot water and something closer to gong fu way of brewing can result in a very enjoyable brew. And that goes for Sencha and even Gyokuru! Caveat: for me that worked only with organic and single origin teas.
A lot of these Japanese cultivars have assamica genetics which gives them unique aromatic properties at the expense of being prone to bitterness. I say that but I strongly suspect that those unique aromatic properties and bitter elements are inseparable, that to get one you have to have the other, even if the genetics are not inzatsu. This can be noted in benzaldehyde, which gives Shizu-7132 it’s distinctive cherry leaf aroma but is also bitter.
I just infused a sencha from Thés du Japon, which I also drank yesterday. Comparing first infusions, yesterday I infused at the recommended 60 degrees C (140F) for 60s in preheated teapot, today 70C (160F) for 30s without preheating. Today's result was much better to my taste. The obvious next try would be 60C in a non-preheated pot, but I have not tried it yet.
First infusion, the tea was about 63C once poured in my cup.
I tried a second infusion with the same water temperature and same duration, just to single out the effect of leaves. The teapot and leaves had cooled down quite a bit, though not entirely. The temperature was about 60C in my cup.
Third infusion, my kettle overshot by a couple degrees C, and the final water temperature in the cup was still 60C. It makes sense that the more water the leaves have absorbed, the bigger an impact they will have on temperature.
In all cases, I poured out to a preheated double-wall cup, so the measured temperature should be very close to the final temperature in the teapot.
Obviously, the results will vary depending on the teapot, ambient temperature, time between steeps, but the above seems like anecdotal evidence that increasing the water temperature by 5C between first and third steep only compensates for the impact of wet leaves on water temperature.
Now, what I would like to do is evaluate how quickly the teapot and leaves bring the temperature down at the beginning of the steep. It is hard to figure out how much of an impact a quick exposure to higher temperature might have on the result, but knowing how fast the temperature drops due to the thermal inertia of the "system" is something I have wanted to play with for some time, maybe comparing how different teapots react to the same well-controlled parameters.
I did one more test, where I put the thermometer tip in the teapot at the time of pouring on fully-expanded, cooled leaves. Water temperature at 72C.
Although my thermometer reacts quite fast to temperature changes, at no time did I see temperatures above about 62. It is as though the water was being cooled on contact as I was pouring. This was not very surprising to me, as leaves have so much surface area for heat transfer to occur. If you believe in "shocking the tea" with an initial burst of higher temperature on infusions other than the first, then you have to believe that this shock does its job very, very quickly, basically on contact with the leaves before they are submerged.
Stated otherwise, if you think your tea needs high temperature, you should probably preheat your teapot for the first infusion, and perform subsequent infusions in quick succession.
What did surprise me a lot was how uneven the temperature was. At first, I thought is was my thermometer having difficulty to stabilize, but I found out there was almost a 15C difference in temperature between the top of the water (hottest) and the bottom. This difference was not short-lived either : it remained throughout my test. I do not know if it was mostly due to the higher amount of leaf at the bottom or the higher teapot surface vs. water volume ratio, but I never thought there could be such a temperature gradient inside a small vessel like this.
The next thing I would like to test is how quickly the temperature drops at the beginning of the first infusion (dry leaves). This will probably yield different results, because dry leaves have little thermal inertia compared to wet leaves, and the cooling from the teapot is likely to occur a bit slower than that of the wet leaves. In other words, the "quick burst of higher temperature" might be possible with dry leaves and a teapot that has not been preheated.
Although my thermometer reacts quite fast to temperature changes, at no time did I see temperatures above about 62. It is as though the water was being cooled on contact as I was pouring. This was not very surprising to me, as leaves have so much surface area for heat transfer to occur. If you believe in "shocking the tea" with an initial burst of higher temperature on infusions other than the first, then you have to believe that this shock does its job very, very quickly, basically on contact with the leaves before they are submerged.
Stated otherwise, if you think your tea needs high temperature, you should probably preheat your teapot for the first infusion, and perform subsequent infusions in quick succession.
What did surprise me a lot was how uneven the temperature was. At first, I thought is was my thermometer having difficulty to stabilize, but I found out there was almost a 15C difference in temperature between the top of the water (hottest) and the bottom. This difference was not short-lived either : it remained throughout my test. I do not know if it was mostly due to the higher amount of leaf at the bottom or the higher teapot surface vs. water volume ratio, but I never thought there could be such a temperature gradient inside a small vessel like this.
The next thing I would like to test is how quickly the temperature drops at the beginning of the first infusion (dry leaves). This will probably yield different results, because dry leaves have little thermal inertia compared to wet leaves, and the cooling from the teapot is likely to occur a bit slower than that of the wet leaves. In other words, the "quick burst of higher temperature" might be possible with dry leaves and a teapot that has not been preheated.
As an aside, I did a quick comparison of readings from an IR thermometer and a standard probe thermometer which I trust to be relatively accurate.
Properly aimed (I have a converging lasers model that helps with that), the IR thermometer read about 7C to 10C lower than the probe thermometer. Maybe tweaking the emissivity setting could improve things, but the thermometer was set at the recommended value for water, so I doubt it. I am not sure I would trust an IR thermometer with that kind of measurement, intuitively water in a shallow container does not seem to be a good candidate for IR. My thermometer is not a lab-grade instrument, not by a mile, so maybe a better one could yield more accurate readings.
I would, however, trust the IR thermometer to measure the surface temperature of the teapot. That might be interesting when comparing teapots.
Properly aimed (I have a converging lasers model that helps with that), the IR thermometer read about 7C to 10C lower than the probe thermometer. Maybe tweaking the emissivity setting could improve things, but the thermometer was set at the recommended value for water, so I doubt it. I am not sure I would trust an IR thermometer with that kind of measurement, intuitively water in a shallow container does not seem to be a good candidate for IR. My thermometer is not a lab-grade instrument, not by a mile, so maybe a better one could yield more accurate readings.
I would, however, trust the IR thermometer to measure the surface temperature of the teapot. That might be interesting when comparing teapots.
Question, what water to leaf ratio are you guys using with the stated time and temperature? I typically use about 0.5g per oz of water.
I typically use 4g for about 100ml. This is what I used for the temperature tests above.
Many would use more leaf than that, in which case the temperature drop due to wet leaves would be even higher. For instance, the tea I used for my tests comes with a recommendation for 4g-5g for 70ml. At 5g for 70ml, this is almost twice as much as I used.
Outstanding tests, @faj! The temperature gradient in the vessel is something I’ve noticed before but dismissed, thinking my probe must not be accurate or is delayed. Hearing that you’ve encountered it too makes me want to investigate it further.
The thermal inertia of wet leaves is something I’ve never thought to care about with Japanese teas but perhaps I should since the temp drop can be significant.
I’m glad you like exploring these subjects from a scientific perspective. I think you’ll give Hojo a run for his money!
The thermal inertia of wet leaves is something I’ve never thought to care about with Japanese teas but perhaps I should since the temp drop can be significant.
I have an inexpensive IR thermometer and planned to use it on the wet leaves and teapot interior to check the temp of both immediately before I steep each time. It has a wide margin for accuracy but should give a ballpark idea of what’s happening.I would, however, trust the IR thermometer to measure the surface temperature of the teapot. That might be interesting when comparing teapots.
I’m glad you like exploring these subjects from a scientific perspective. I think you’ll give Hojo a run for his money!
For a while, I have had a hunch that increasing the temperature to "extract more" in later steeps as many people do actually mostly achieves maintaining infusion temperature at a similar level rather than increasing it. I think many would be surprised how much hotter the water needs to be to actually achieve a significantly higher infusion temperature in infusions following the first one (except if the infusions are performed in quick succession, of course).
That makes sense. That would allow, for instance, to compare the drop in temperature if you leave the lid on or not after brewing. Some times the little things have surprisingly large impacts.
Of course, each combination of teapot, leaf amount, level of leaf rehydration, ambient temperature and humidity will have its own thermal signature, so it would not be practical to model every possible combination. Taking a few measurements may help understand why some infusion methods and/or vessels yield different results. For instance, it might be useful when trying to replicate similar results when using different size vessels.
@faj, I tried taking temps just now but soon realized four things:
1) my water temps are way cooler according to this IR thermometer than I ever thought so I may not be a good candidate for testing. Out of the yuzamushi, my water was around 50°, at least 10° cooler than I thought I was doing.
2) I realized I needed to have a consistent temp for water each time or my test would be meaningless.
3) I would need water temp, base leaf temp, tea temps after pour, base wet leaf temps before water.
4) All these measurements messed up my flow and I was getting less tasty tea. A tea version of the Heisenberg uncertainty principle, hahaha!
1) my water temps are way cooler according to this IR thermometer than I ever thought so I may not be a good candidate for testing. Out of the yuzamushi, my water was around 50°, at least 10° cooler than I thought I was doing.
2) I realized I needed to have a consistent temp for water each time or my test would be meaningless.
3) I would need water temp, base leaf temp, tea temps after pour, base wet leaf temps before water.
4) All these measurements messed up my flow and I was getting less tasty tea. A tea version of the Heisenberg uncertainty principle, hahaha!
I have a variable temperature kettle and a decent probe thermometer, so in my case I know the IR thermometer was reading too low when aimed at the water. Maybe your water is not as cool as your IR thermometer says.
Taking measurements does not make tea better, for sure, and can be tedious. I am probably going to have a bit of fun characterizing the thermal profile of my teapots just as a learning exercise, but in the end one wants to know one's tea and vessels well enough to avoid overthinking. Being relatively new to tea, I have a lot to learn, so for me this is a fun way to experiment. I would not want to do that every time I make tea.Baisao wrote: ↑Sat Jan 25, 2020 4:08 pm2) I realized I needed to have a consistent temp for water each time or my test would be meaningless.
3) I would need water temp, base leaf temp, tea temps after pour, base wet leaf temps before water.
4) All these measurements messed up my flow and I was getting less tasty tea. A tea version of the Heisenberg uncertainty principle, hahaha!
@faj
When you said you aimed IR thermometer at the water, did you aim the red dot at the center of the vessel? If so, I think the temp you got was the temp of the bottom part of the water or vessel.
If you aim the laser at the lowest point of the inside wall and gradually move up along its wall, you’ll see that the temp will be gradually higher too.
When you said you aimed IR thermometer at the water, did you aim the red dot at the center of the vessel? If so, I think the temp you got was the temp of the bottom part of the water or vessel.
If you aim the laser at the lowest point of the inside wall and gradually move up along its wall, you’ll see that the temp will be gradually higher too.
Good point. I aimed the laser various ways and could not get a reading that felt right. I did not specifically try to do what you suggest (will try it next time to see how close I get to the reading from the probe when putting the probe close to the side of the pot).
This being said, if you are right, wouldn't the reading still be that of the surface of the clay, just a location where the clay is at a higher temperature than at the bottom?
IR thermometers read from a circular region the size of which changes with distance (at least mine works this way, and has two lasers to help figure out the area the sensor is covering). You have to make sure you are at the right distance, actually stepping back from the teapot. I do not see any advantage over a probe thermometer, either in speed, flexibility or accuracy.
I definitely have more intuitive, practiced approach to tea.
I remember when I first began teaching GFC classes I took measurements of my parameters, something I had not done in literally a decade or more. I was astonished by how far off my actual parameters were from what I thought I was doing!
I was using more leaves and cooler water than I thought. For years my process was leaves added by sight and water pulled when my kettle made specific rattling sounds (chosen to target certain aromas).
Not long after I had to replace my kettle and it was more silent so I had to return to using a thermometer until I got used to it. I still use a thermometer because I use two different kettles and I don’t want to loose heat by opening the lid to look at bubble size, especially over a brazier, where it can take 20 minutes for a liter to come to a boil.
I remember when I first began teaching GFC classes I took measurements of my parameters, something I had not done in literally a decade or more. I was astonished by how far off my actual parameters were from what I thought I was doing!
I was using more leaves and cooler water than I thought. For years my process was leaves added by sight and water pulled when my kettle made specific rattling sounds (chosen to target certain aromas).
Not long after I had to replace my kettle and it was more silent so I had to return to using a thermometer until I got used to it. I still use a thermometer because I use two different kettles and I don’t want to loose heat by opening the lid to look at bubble size, especially over a brazier, where it can take 20 minutes for a liter to come to a boil.
I also think IR thermometer is useful for some applications only, obviously not for liquid.faj wrote: ↑Sat Jan 25, 2020 9:18 pmGood point. I aimed the laser various ways and could not get a reading that felt right. I did not specifically try to do what you suggest (will try it next time to see how close I get to the reading from the probe when putting the probe close to the side of the pot).
This being said, if you are right, wouldn't the reading still be that of the surface of the clay, just a location where the clay is at a higher temperature than at the bottom?
IR thermometers read from a circular region the size of which changes with distance (at least mine works this way, and has two lasers to help figure out the area the sensor is covering). You have to make sure you are at the right distance, actually stepping back from the teapot. I do not see any advantage over a probe thermometer, either in speed, flexibility or accuracy.