What is the white foam that shows up on tea when the water isn’t hot enough?

Question

What is the white foam that shows up on tea when the water isn’t hot enough?

In: Chemistry

Answer 1

It doesn’t happen when the water isn’t hot enough, it happens when the water is too hard, that is, it has too much minerals in it, which react with some substances in the tea. Boiling can remove some of the hardness, though.