It would only be able to heat the tea to above 100C if that point of zero nucleation remained undisturbed, and the tea held directly within it; in other words, it’s not possible.
Assuming there’s an amount of water within the cup that is above 100C, while the rest is at or below 100C. As soon as you grab the cup out of the microwave, the water will start to slosh around in the cup, equalizing the temperature. If there are any major hot spots remaining, they will be well below 100C, and almost completely equalized when the tea bag is added.
It would only be able to heat the tea to above 100C if that point of zero nucleation remained undisturbed, and the tea held directly within it; in other words, it’s not possible.
To be clear, the liquid water flashes into steam as soon as it contacts the leaves, so technically it isn’t the supersaturated water itself heating the tea over 100º. But the steam it produces is above 100º, and that’s what heats the tea.
It would only be able to heat the tea to above 100C if that point of zero nucleation remained undisturbed, and the tea held directly within it; in other words, it’s not possible.
Assuming there’s an amount of water within the cup that is above 100C, while the rest is at or below 100C. As soon as you grab the cup out of the microwave, the water will start to slosh around in the cup, equalizing the temperature. If there are any major hot spots remaining, they will be well below 100C, and almost completely equalized when the tea bag is added.
To be clear, the liquid water flashes into steam as soon as it contacts the leaves, so technically it isn’t the supersaturated water itself heating the tea over 100º. But the steam it produces is above 100º, and that’s what heats the tea.