Solubility. Convection. Boiling. And why the kettle is the perfect hot-tea.
Black and herbal teas are best steeped at close to 100°c/212°F. Would you use a kettle or a microwave to boil the water to make that perfect cup of hot tea?
We recommend the kettle. When we boil water in a kettle and it begins to bubble fiercely, all the water will be at 100°C. This is due to convection currents. Water at the bottom heated by the stove rises to be replaced by cooler water, which becomes heated and rises as well. The cycle repeats itself until all the water reaches boiling temperature.
A microwave, on the other hand, first heats the water near the sides of the cup. According to What Einstein Told His Cook, “microwave energy is absorbed only by the outer inch or so of the water in a cup [and] the resulting heat” is transferred by conduction inside. This takes time. More crucially, this means it is difficult to know when the cup of water is at a uniform 100°C; unlike boiling, different parts are likely to be at different temperatures. It is simply not as hot.
This is why we are more likely to get a delicious cup of hot tea from water that has been freshly boiled in a kettle. The caffeine (and flavor and color) of tea leaves is more soluble in hot water than warm or cold water. Water that is evenly boiled thus does a better and excellent job of dissolving and extracting the caffeine, color and flavor.
When you need more water to make another round of hot tea, why not go for boiling water? And just like the phenomenon of cooling hot liquids by cooling, the physical world has once again given us a neat and simple visual cue to know when our water is at the right temperature for a perfect cup of hot tea!
What are your favorite hot teas? Share them with me!
Like this? Make me your hot-tea and like me to discover more. All you need is a minute a day to explore the world’s marvels through the phenomenon of food!
photos: in order – depositphotos/maxxyustas; kvkirillov; aragami12345; monkeybusiness; gdolgikh