As many tea drinkers keep a comforting cup of tea within reach throughout the day, a common question has arisen: how do I keep my tea hot?

I admit that I don’t have that problem because my tea disappears so quickly that it doesn’t have time to cool before I fill the cup again. As a result, many consumers might be considering purchasing an electric cup or mug warmer. There are numerous choices on the market, with some high-end cordless models priced as high as $125.

I decided to conduct an experiment to judge the optimum temperature for enjoying the tea in my cup. So, I steeped three teas – Keemun black, Sencha green, and blueberry fruit infusion – for five minutes, poured the hot tea into an 8-ounce mug, and took a sip once every minute as the liquid cooled.

Dedicated tea drinkers will not be surprised to learn there is an optimum temperature where all these teas release their peak flavors.

The black tea and fruit infusion were steeped with boiling water, which cooled to 170° F after a five-minute steep in a small teapot. After allowing the tea to cool for one minute in the mug, the temperature decreased to 160°; too hot to drink. At two minutes, the temperature was 155° and still undrinkable. It took three minutes for the black and fruit teas to cool to a drinkable temperature of 150°, still too hot for most tea drinkers. After four minutes in the cup, the tea was 147° at the top of my perfection scale.

These two teas continued to be quite good until the 7–8-minute mark. At that point, the temperature had cooled to 135°, and the tea in the cup began to taste tepid. At 10 minutes and 130°, I needed a warm-up pour from the teapot. Finally, at 16 minutes and 121°, I was ready to toss the tea and start over.

The Sencha green tea trial delivered similar results. Remember that green tea should be prepared with water no hotter than 175°. After a five-minute steep, the Sencha entered my mug at 150° and was ready to drink. It remained at optimum flavor for four minutes. Unfortunately, this tea began to fall from my favor as the temperature dropped below 140°. After 15 minutes in the cup, the tea reached a very tepid 112°, and the end of its goodness.

For me, the optimum temperature to enjoy these three teas was between 140° to 150° or one to seven minutes in an unheated mug.

There is one warning to keep in mind. The International Agency for Research on Cancer has stated that beverage temperatures of 150° and more can increase esophageal cancer risk. In addition, the agency’s research (based on men) suggests that drinking very hot liquids could double the risk of developing this cancer due to the potential damage and burning caused to the throat.

Are you still considering buying a mug warmer? Drinking your tea within five or six minutes after pouring might be prudent. Save that $125 to buy good tea!

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Bruce Richardson’s article first appeared in the May/June 2021 Edition of TeaTime magazine.