Comment by korginator

The article misses the other very important points - brewing time, and water:leaf ratio.

The taste of your tea depends a lot on the quality of the leaves. I've used a wide range of Sencha leaves, some of them absolutely hate high temperatures beyond 70℃ while some others happily brew in 85℃.

Brewing times can drastically affect the bitterness of the tea even at lower temperatures because of how the catechins are extracted. In my experience, the first 30-60 seconds can make or break the taste - this is when the temperature must be just right.

I've got a variation to tweak my tea's taste by starting to brew at a slightly lower temperature for about 60-90 seconds and then adding some water at 85-90℃ at this point and letting it brew a bit longer. Some types of sencha teas respond well to this approach, and I feel this brings out a little more of its caffeine content and a hint of bitter / astringent flavours while not overwhelming the overall taste.

It also depends on what you're trying to achieve with the tea. Using the exact same leaves, I sometimes like to brew a very mild warm tea, and at other times the same leaves can be brewed at a higher temperature for a more full bodied tea.

My approach is to experiment with a new batch of leaves to quickly identify its boundaries re: temperature and time, and that gives me a lot of room to play with and experiment :)