Further exploring TdJ's ultra-short steamed, lightly fired Tōbettō after my
first session. 8g, 120ml 63°C, 1m20s steep. This time I warmed the teapot more carefully. It takes time for the water to cool down to 63°C in a samashi, so if you empty your teapot of warming water and put in leaves too early, out of habit, they may become too cold for the brew while you wait. The warming water was exactly 60°C when I poured it out, then I put the leaves and quickly poured for the steep at 63°C. Result was very different from my first attempt (6.6g, 100ml 60°C, 1m10s), where the first infusion was a bit weak. Not sure which variable (slightly hotter water, higher volume, proper warming) contributed most, but it was a phenomal steep. More umami, much more sweet, much less bitter, delivering a full thick soupy kick, like a deep-steamed sencha, but without any grassy or hayey notes whatsoever. Some notes are reminiscent of a sweet matcha, some go in a fresh, grainy direction, maybe like sweet corn or a genmaicha (but without any of the burnt/toasty notes, obviously). Very satisfying. Second steep (usually my favorite for sencha) at 64°C for 30s was also excellent, no bitterness, a tiny bit inferior to #1 (will try 40s next time). Things were going so good, I thought I had gotten the knack of this tea, but #3 at 71°C for 1min was again overkill, resulting a bitterness that flattened the complexity. #4 (at 71°C) was better, #5 ok/good, #6 at 75°C/3mins not as great as in the previous session. I also drank #7 and #8, which brought interesting notes with increasingly hotter water, but I should have just pushed #6 harder to conclude with a very good steep.
As Baisao noted (and the seller instructs), this tea seems to really like cooler temps. I think it's critical for the first 3 (4?) steeps, but then you should not be afraid to get much hotter. My next attempt will be 63°|65°C|68° (1m20s|40s|50-60s) for the first three, and then go according to feeling but push hard, esp. after #4, aiming for a total of 5 or 6. I have the budget-unfriendly feeling that this may turn out to be my favorite sencha, esp. if I am able to better tame/distribute the bitterness consistently. (I usually prefer full-bodied, deep-steamed sencha, don't mind / actually like grass and hay notes.)