Most of us in the western world are brought up thinking that all we need to do to make a cup of tea is heat water, add tea, wait a few minutes, then drink it. Although this is basically true, paying attention to the water temperature will help get the best flavor from your tea.
Chances are you’ve wondered why your tea doesn’t always taste great or doesn't even taste the same from day to day. While this could be caused by several factors, water temperature is an important one to consider. (See Water—The Mother of Tea for information about water quality.)
Every type of tea has a “right” temperature. When tea is brewed, tannins, amino acids, aroma and flavor compounds are released from the leaves. Some kinds of tea require less heat, while others need more to maximize their distinctive attributes. Brewing at the optimal water temperature for each kind of tea allows the compounds to be released in a balanced way and leads to great tasting tea.
Water temperatures that are too hot dissolve tannins and destroy the other desirable compounds in tea. Thermal shock from overly hot water can also burn sensitive tea leaves. The result will be a bitter, astringent, and unbalanced brew.
The primary rule to remember when heating water to brew tea is to never boil the water.
It's possible to burn the tea leaves (whites and greens are particularly susceptible) even in water that's the right temperature. One method to avoid shocking tea is to rinse the leaves in cold water before brewing. Another strategy is to pour the heated water down the side of the pot or cup and avoid direct contact with the leaves.
At the opposite end of the spectrum, you also don’t want the water temperature for brewing tea to be too cool. The same compounds that are destroyed with over-heated water won't dissolve properly in under-heated water. The finished tea will definitely lack balance and simply won't have as much taste. A longer steeping time may compensate, but only a bit.
To find the right water temperature for your tea, ask the salesperson at your tea shop or read the label on any packaging. It's important to stay within the recommended ranges, but remember that how your finished tea tastes is a matter of personal preference. You might need to experiment a little to find the temperature that suits your taste best.
Some general guidelines for the different categories of tea follow if temperature information isn't available.
Rolled oolongs and other teas in pearl form are notable exceptions to the guidelines. These not only withstand, but are best when brewed in water near boiling. For these, more heat is required to slowly unfurl the leaves and release their distinctive aroma and flavor compounds.
How can you measure the temperature of the water? Here are a few ways:
1. Use a thermometer. A candy thermometer works well. Or you can also buy a digital tea thermometer specifically for use with tea. Cost: $10–20
2. Purchase a tea kettle with a built-in thermometer. These kettles are getting easier to find as tea drinking becomes more popular in the U.S., and some even have settings for specific types of tea. Definitely convenient, but a little pricier than a thermometer. Cost: $40–100
3. Use your senses. With a little practice and experience, you can judge water temperature by eye and ear. See the details that follow. Cost: Free
You’ve probably heard the expression “a watched pot never boils.” Well, in order to judge the temperature of the water for tea using your ears and eyes, you have to watch the pot—and certainly remember to never boil the water. So maybe the adage should be changed to “watch the pot so it never boils.”
When using your senses to gauge the temperature, you’ll need to pay attention to the bubbles and steam rising from the water while listening for different sounds. These change during three different stages of heating water. If using a saucepan you’ll be able to see as well as hear the changes. If you’re using a kettle then you’ll need to rely mostly on sound, although you might also see some steam escaping through the spout.
Watch our video Heating Water for Tea here.
Stage 1. Tiny bubbles rise through the water to the surface. Look carefully and you’ll see steam rising in small, gentle streams. You’ll begin to hear the water make a low humming sound.
Water at this temperature is sometimes called “baby water” and is considered unhealthy. It is never used for making tea.
Stage 2. You’ll start to see continuous streams of larger bubbles that look like small balls tumbling around in your pot. Steam will begin rising vertically with more volume. The water will start to make popping sounds.
This is called “mature water.” Use water at this stage for brewing tea. The beginning of Stage 2 is best for white and green teas; the later part is best for oolongs, black teas, pu'er, and rolled teas.
Stage 3. Water bubbles noisily in furious waves with high volumes of steam clouds rising. This boiling water is called “old man water,” and boiling water is never used for making tea.
Although using your senses isn’t as precise as using a thermometer, you’ll get the hang of it quickly, especially if you tend to drink the same kind of tea regularly.
Most modern electric tea kettles without thermometers stop automatically when the water starts to boil rapidly. Unfortunately, this is too late for brewing tea. If using one of these, listen for the sounds described above, and stop the kettle before it boils. WARNING: Never lift the lid during heating as the escaping steam can burn you.
Finally, if you have a choice between using electricity or gas for heating water, use electricity. The smell of gas can linger in the water, affecting the taste of your tea. This effect should be less significant if using a kettle with a closed lid.
Let's end with this interesting fact! Historically, charcoal was used as fuel to heat water for tea and was called “the friend of tea.” Unlike coal and firewood, charcoal doesn't produce smoke that infiltrates the water and makes the tea taste bad. Today we might think of charcoal as the friend of tea because it’s used in water filters that purify our water. But that’s a different subject you can learn more about at our Better Tea through Testing link.