LuckyMe wrote: ↑Wed Jan 22, 2020 1:34 pm
Baisao wrote: ↑Wed Jan 22, 2020 1:09 pm
LuckyMe wrote: ↑Wed Jan 22, 2020 12:41 pm
I notice pour time affects the flavor of sencha in a couple of situations. One is when I'm pouring back and forth between cups instead of directly into a pitcher or single teacup. Although serving tea in this manner is fun, it naturally prolongs the pour thus bringing out more bitterness.
Another is flash steeping. Sometimes, I'll flash steep using near boiling water for the second cup and an extra 5 or 6 seconds can affect flavor. This is one time when metal strainers do a better job than sasame.
Temperature is a bigger (sole?) contributor to bitterness than steeping time. You can steep sencha or gyokuro overnight in the fridge and it isn’t bitter at all. I suspect there is something wrong with your temperatures, especially as you mention flash steeping sencha. I can think of no reason for doing this with sencha.
If there's one thing I've learned from gongfu brewing, it's that time can be just as much a contributing factor to bitterness as temperature. I ambient brew green tea all the time and find that bitterness begins setting in if left to steep longer than 2 hours. Same thing with cold brewing if you leave it in the fridge too long. The key to the optimal brew is balancing all of the variables which are temperature, time, leaf quantity, and water ratio.
Flash steeping the second cup was recommended by one Japanese vendor for fukamashi. It works with better with some teas than others. Hojo has a similar method for flash brewing sencha.
I think there may be some details missing. The bitter components of tea are mostly insoluble below 80°C. It's conceivable that a poorly processed tea could become bitter with room temperature water but that is not something I have experienced or have heard of. I don't drink much fukamushi sencha but perhaps the extra steaming has caused bitter compounds to be extracted and deposited onto the exterior of the leaves, released into solution when water has been added.
I don't know what expert recommended using boiling water for a brief steeping of sencha but I have only heard of this in two exceptional cases:
1) An experiment where the hot steep is combined with other, more moderate steeps, to assess all characteristics of the tea.
2) Making zairai, which has so very little bitterness that it can be boiled (!), but it is an exception because it is seed grown and not a propagated vegetative like the cultivars used in 99.99% of sencha.
The process for the second steep is to use the same temp water as the first steep, then pour water into the vessel, oscillate the vessel gently 5 turns, then pour off. Those 5 turns get the leaves off the upper wall of the vessel that were left there from the first steep and also serve as a timing mechanism to tell you when to pour. In fact, if you look at the steps for senchado you will see that many of the steps serve dual duty for cleaning and timing.