I'm no luddite. I like technology in many instances, but I'm often considering the simplest way of brewing tea. Over time, I've tried brewing a tea with boiling water for which I'd normally have used much cooler water. Talked with a Taiwanese tea shop owner a while back, and she insisted that she used very hot water for her best High Mountain Oolong. Tea that I'd been very cautious with until that point.
Then a few people in the Google+ Hangout mentioned that they brewed many sorts of tea with water much hotter than I was accustomed. Rather than talk about specific temperatures, one or two of them mentioned different sorts of boiling water as it's described in the Chinese cooking culture.
The thing I remembered from the discussion was 'fish eyes'. The water starts to boil and the size of the bubbles can be described as 'shrimp eyes, crab eyes, fish eyes, rope of pearls, and raging torrent'. Tea Trade Peter found that when I asked about this in a Tea Trade forum (fish eyes).
I especially like the quote that Bram included in the discussion, so I'll leave you with that:
When the water is boiling, it must look like fishes’ eyes and give off but the hint of a sound. When at the edges it chatters like a bubbling spring and looks like pearls innumerable strung together, it reaches the second stage. When it leaps like breakers majestic and resounds like a swelling wave, it is at its peak. Any more and the water will be boiled out and should not be used.
The Classic of Tea (Cha Ching) by Lu Yu (~ 800) (translation FR Carpenter)
(photo source: www.2dayblog.com)