If you've ever had a furious debate about the ungodly act of microwaving your cup of tea and how "it's the same" as boiling the kettle, you're about to lose — not only to Britain but to science.
Researchers have explained the process your zapped cuppa goes through in a new study published in the American Institute of Physics' peer-reviewed online journal AIP Advances, and why you might not be getting the best results from making it this way over the traditional kettle/stove method.
The study, conducted by researchers at the University of Electronic Science and Technology of China, looked at how heating liquid works in a microwave, and how the electric field that acts as a warming source causes the liquid to end up different temperatures at the top and bottom of the cup. A good cup of tea is all about getting uniform temperature throughout your water and, though many scholars have studied uniformity and how to solve it within the microwave itself, these researchers have offered up a different possible solution (more on that later)...
But if you're throwing your cup of water in the microwave for 90 seconds, like the researchers did, the device's electric field heats it from all angles, not just from below, so while the top part of the cup's water may be sitting at boiling point, the bottom may not. "Because the entire glass itself is also warming up, the convection process does not occur, and the liquid at the top of the container ends up being much hotter than the liquid at the bottom," reads the study.
So, your microwaved cup of tea is hotter at the top than the bottom. Let's take a 30-second mournful-staring-at-the-floor break...
Notably, the Academy wrote that teas steeped in cold or iced water release fewer of their bitter ingredients and more of the sweet, so it doesn't always have to be hot stuff. But whatever tea you're making, all of this inevitably gets thrown off balance when your cup of water is not the same temperature all the way through, say, if you warm the water in the microwave and dunk a teabag in it as opposed to pouring kettle-boiled water over the tea in a pot or bag. You've got a small window for perfect brewing temperature, whether you're making green tea (70°C), oolong tea (90°C) or black tea (95-98°C). So if the water goes from hot to less hot levels in the cup, it will brew differently — and when you start jiggling the teabag around the temperature can change too, so it might be less warm than you need it to be. ..
Look, microwavers, I get it, it's quicker. And if you want something to come back at your opinionated, traditionally-made tea drinker pals, a food scientist from the University of Newcastle in Australia reckons microwaving your cup of tea is the key to getting more health benefits from the beverage (note: health, not taste, benefits).
I'll be sticking to my kettle method, but you do you.
Just know Britain is judging you.
I guess stirring the microwaved water isn't sufficient to "distribute" the hot water, so hmmm.
Ah, but this research is from China, and we all know that China is 屁股 (pigu), so... ;-)
ReplyDeleteAre you saying, Don't trust China?
ReplyDelete