Putting a cup of water in the microwave and heating it to prepare tea surely seems effortless. All you need to do is pull out the cup and add the tea leaves or tea bag. However, there are a few things that are wrong about using the microwave to heat up water. It can not only destroy the flavor of the beverage but also puts you at risk!
Several people have reportedly injured due to microwaving water for tea as it was heated above the normal boiling point.
On the stove, water reaches 100 degrees Celsius to start boiling if there are bubbles of air or steam present. But, the water can get superheated above this temperature in the absence of bubbles. While saucepans or kettles that use a filament for heating, microwaves heat the liquid directly by passing through the vessel, thereby making the contents hotter than the cup. Microwave vessels are smoother than saucepans or kettles, and that's why the air bubbles don't adhere to the sides of the vessel and the water doesn’t boil, which in turn, makes it unstable.
Another major fact is that the handle of the cup is cool to the touch when you pour water from a kettle. On the other hand, placing the cup in the microwave when heating water for tea makes the handle hot as well. This puts you at risk of finding the cup intolerably hot on pulling it out, and you may end up getting burnt.
A liter of superheated water can produce 3 liters of steam, thereby boiling aggressively and exploding out the vessel. It can also explode when you add tea bags or tea leaves to the water or use an object to stir it.
Microwaves make the water too hot in some spots and too cool in others, which in turn, makes for a poor cup of tea. The appliance shoots waves into the water at random places, thereby leading to a rapid vibration of the water molecules at those spots. If not allowed to heat for long enough, it builds isolated pockets of hot water in the larger, cooler portion. The signs of boiling shown by such liquid can be misleadingly and not reaching a uniform temperature of 212 degrees. In such cases, the steam that rises from microwaved water is actually moist vapor that evaporates off the surface of the liquid, which further condenses into mist when it touches the cooler air.
However, this problem arises only when you are using a really huge cup as microwave wavelengths are nearly 4-inches, so you mostly get an evenly heated liquid, especially if you put it on the carousel's edge and stir the water after heating.
You don't have any temperature control to heat water for tea when you use the microwave to get the task done. This ends up in too hot or too cold water for the tea that you need to brew. So, you don't achieve the perfect temperatures and times and for steeping tea.
Different types of tea call for certain types of hot water. For example, pu-erh, black tea, and some oolongs need boiling water. If it's not hot enough, the resulting blend will be less flavorful and tepid. Green tea needs 176 degrees Fahrenheit for steeping, while herbal tea calls for 210 degrees. The problem lies in the fact that placing the mug in the microwave doesn't give you any idea how hot the water is. On the other hand, kettles are crafted to heat tea to 212 degrees, which is the ideal temperature for most varieties.
The flavor-creating compounds in tea leaves start dissolving when the leaves come into contact with hot water. They are suspended in the water under the right conditions, creating the perfect blend of leaf extracts and water. In fact, some compounds in the leaves are also cooked, bringing out the best flavor and benefits of the blend.
But using the microwave lowers the temperature accuracy of the water that’s essential to a great cup of tea. Providing a heat source from underneath heats the water evenly by making the hot water rise and the cooler part fall. The curved shapes of teapots and kettles make them great at this. As stated above, the microwave doesn’t heat the water evenly and sometimes, you must overheat it to remove the cool spots. Now, adding tea leaves to overheated water harms the aromatic compounds while also creating a bitter taste.
Often at the workplace or other spots where you don't have any choice than simply microwaving the tea water, you can eliminate all the risks and problems with the same by following the below tips.
Use a thermometer to check the temperature after you microwave the water before adding the leaves, thereby brewing a better cup of tea than without checking it.
Don't place the tea leaves or tea bag in the water before microwaving it. Instead, microwave the water first, followed by placing the tea in it or pouring it over the tea. Putting the tea in the water before heating will begin the steeping process while the water is still cool. Also, it will steal away your control over the temperature and time of steeping.
Preheating the cup before you microwave water for the beverage ensures that the water temperature doesn't drop on pouring it into the cup.
Superheated water can turn out to be extremely dangerous as it is likely to erupt instantly when the tea leaves are placed in it, thereby causing burns. You can avoid superheating by not using a glass mug and distilled water so that there isn't any surface to let the bubbles condense on. Prefer going for tap water.
A strong microwave can boil water in a minute, whereas a less powerful one might boil it in three minutes. So, it's essential to know the particular microwave you are using in order to reach the right brewing temperature and prevent it from superheating.
Microwave safe vessels don't absorb the heat of the appliance. This prevents problems like uneven heating, as well as prevents the mug from heating faster than its contents, thereby avoiding cracks, melts, catching fire or burns.