All images ©2009 Jennifer Leigh Sauer
WATER TEMPERATURE ALSO INFLUENCES the final cup, and tea masters are vigilant about heating their water optimally to match the tea they are brewing. However, they determine the "readiness" of the water in different ways--visually, auditorially, and electronically.
Some look for visual signs of the water temperature to determine when the water is heated properly for the particular tea they intend to brew. You may have heard that some tea masters look for "fish eyes" in the water. This is when medium bubbles form just before the water moves towards a roiling boil, and when the water is ready for oolongs. The way the steam leaves the spout of the kettle--in wisps or in gusts--also signals the water's readiness to some tea masters.
Lu Yu said:
When at the edges it chatters like a bubbling spring and looks like pearls innumerable strung together, it has reached 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.1
David Lee Hoffman listens to the water. During our tea time together, as the water began to get closer to boiling, he stopped the conversation and said "Listen!" as he waited in anticipation for exactly the right crackling or rumbling noise to emit from the iron kettle over the fire. A skilled sound man, Hoffman has a keenly trained ear which he puts to good use as a tea master. He said he also pays attention to the way the steam rises from the spout at different temperatures.
Many tea masters simply use automated kettles that brew water to a pre-selected temperature, and still others in the slow food movement who like to be numerically exacting without the aid of electronic technology, will use a simple kitchen thermometer meant for liquids. (Note: these thermometers have a range that does not exceed about 220°F and will melt if accidentally use in the oven).
I rely on a combination of visual and auditory methods to brew water to the right temperature. I watch for the intensity and velocity of the steam coming from the spout of the kettle, and if I am busy doing something else while the kettle is heating, I listen for a certain sound I have come to recognize when the water is close to boiling (kind of like popcorn popping). If the whistle blows before I reach the kettle, I've failed. I just recently had to buy a new tea kettle, and notice that it makes different sounds than the old one, so I am having to learn the language of this new tea kettle.
You will also want to become familiar with the relationship between tea type and water temperature. Here are some basic guidelines, which are meant to be experimental baselines. Green and white teas tend to require cooler water temperatures, usually between 160-185°F; oolongs do well in higher temperatures, approximately 185-205°F; and black teas can usually be steeped in water 205°F to boiling (212°F). Playful experimentation might also lead you to discover some of the secrets of tea, such as steeping an oolong in cooler-than-optimal water will bring out sweeter notes in the tea.
This is just a brief overview of water for tea. Each aspect regarding water for tea is a subject in itself that some tea experts delve into with great vigor and in depth. Collecting and heating water is the first step to brewing good tea. But however you brew tea, be sure to drink, dream, share, and be merry.
1 The Classic of Tea, translated by Francis Ross Carpenter (Ecco Press, 1974)