Some would say that making a cup of tea using the microwave is an affront to civilised society and the heritage of Britain, India and China.
For decades, centuries, in some cases millennia, making tea was a simple and flawless process that didn’t need to be digitised or improved on. Do you have a pot and boiling water? Good. That’s enough. Then one day, Percy Spencer decided to invent the microwave, a fine piece of technology that has helped out a lot of people across the world.
But it impacted tea in the worst way. Now Americans — who don’t tend to own kettles — think it’s okay for a cup of tepid tap water to be placed in a microwave for a minute and consumed like normal.
There may be Americans reading this, scratching their heads, still unsure what is exactly wrong with microwaving tea. Below are a few pointers, backed by science no less!
Why shouldn’t you microwave tea?
The way water is boiled and heated is more important than you think. When you heat water on a stove or in a kettle, the source of that heat warms the pot or kettle from below. What follows is convection: the hot water from the bottom moves to the top, allowing the cooler water to get access to the heat source, creating an even temperature throughout.
Putting a cup of room temperature or cold water into the microwave exposes it to heat from all angles, not just from below, so while the top section of the cup may be hot, the bottom part may not. As the entire cup itself is heating up, convection doesn’t occur. That said, this won’t be a problem if you’re someone who never tends to finish a cup of tea.
Why should you microwave tea?
Quan Vuong, a food scientist at the University of Newcastle in Australia, claimed that microwaving tea activated 80% of its caffeine as well as amino acids and antioxidants like theanine and polyphenol. He also claimed it made for a better-tasting brew overall.
This research was undertaken a decade ago in 2012, but came to light after British drama Broadchurch showed a character heating a cup of tea in a microwave. A scandal erupted, a discourse followed, and Vuong’s findings went viral. But what is the precise way to do it? Surely most ways are wrong.
Add water and a tea bag to a microwave-safe cup of your choice and heat for 30 seconds on 50% power. Allow the cup to sit for a minute before discarding the teabag. Vuong says you should do this three times a day to reap the benefits of quickfire tea.
Can you microwave milk?
Heating milk in any device can pose risks. Too long and at best you’ll end up with a scorched bottom or a layer of skin on the top. This skin can often be dissipated by stirring, but if your milk is scorched, there’s no going back. Unless you have a really strong stomach, it’s unusable.
Be careful, if you are microwaving milk and do so very slowly. Microwaving for two minutes or more is going to cause the boiling milk to overflow. Anywhere between 60 to 90 seconds should be enough to heat milk, but make sure you stop to stir every fifteen seconds.
If done correctly, there is little risk when it comes to microwaving milk. A final word of advice, however: do not re-chill heated milk as the risk of bacterial contamination is extremely high. Unless you like the idea of living in the bathroom for a whole day, avoid this at all costs.
Alternatively, you could not heat your milk at all. After boiling some water in microwave, a splash of cold milk isn’t going to plummet the temperature of your tea.
Can you microwave a teabag with a staple?
Some teabags come attached with a string stapled to it, leaving many worrying about whether or not putting them in a microwave would be a fire hazard. As long at the staple is immersed in the tea, it’s perfectly safe.
There are also concerns about the prospect of the staple causing toxic and harmful chemicals into the brew. Again, this has been debunked and there is nothing to worry about. Orhan H. Suleiman, MS, PhD, wrote: “There is absolutely no evidence to suggest that exposing staples to microwaves will cause any toxic or harmful chemicals to be released. Microwaves will be reflected by the metal, not absorbed.
“Although there has been some research suggesting that some plastics, if heated, may release some very low levels of some chemicals, these amounts are not considered hazardous. Definitely use products that have been labelled for microwave use and for storing or heating foods.”
Can water be superheated in a microwave?
Superheating, otherwise known as boiling retardation, is when water is heated to a temperature above the boiling point without actually boiling. This can cause explosions in your microwave if the dissolved minerals in your tap water are not big enough to serve as nucleation sites for the bubbles to react with.
There are many ways to avoid superheating happening. You can use a glass or ceramic bowl safe for microwaving. Do not cover with a lid of any kind. Put a non-metallic object in the container if possible such as a wooden chopstick sticking out of the water to break the surface tension.
As stated above, heat in short intervals. Stir the water each minute, monitoring its development, checking to see whether or not it has boiled yet. Tap the container to disturb the surface tension of the water molecules. When tension is broken, trapped heat released. This is a nice way of saying “explodes” so be very careful when doing this.
Finally, when removing your water from the microwave (this should go without saying) do not use your bare hands. Fetch some mittens or a cloth of some kind to prevent burning your water from the container or a random drop of boiling water.