The water in the microwave warms up unevenly. And when it does warm up to 100 degrees, it’s hard to notice, because there is no steam. This is due to the nature of the interaction of microwave waves and water molecules.
The temperature of the water is very important for the proper preparation of tea. The water should come to a boil before you make tea. This is easy to do with an ordinary kettle. Here the water warms up to the boiling point quickly and evenly.
In the microwave, the water will heat up due to the energy of microwave waves. They act pointwise on the molecules and make them move chaotically. As a result, the water heats up unevenly, hot molecules appear in it among the not yet heated liquid.
Evaporation from the surface can create the illusion of steam rising from a mug of hot water, but in fact the water remains cool at this moment.
If the water is heated in the microwave for a long time, it reaches the boiling point, but does not boil, as with the usual heating, but continues to gain temperature. So, if there is a need to use a microwave oven for boiling water, then you need to set the “100 °C” mode for a minute. And don’t wait for bubbles to appear. But there will still be no guarantee of uniform heating.
Warming water for tea in a kettle is both more convenient and safer.
A microwave is an ideal tool for many kitchen tasks, but brewing tea is not one of them.