Jeremy W. asks: Is it true that drinking tea made from twice boiled water is bad for you? Twice boiled water is definitely bad for you… Except, this water is actually still not bad for you, unless it was already bad for you to begin with (i.e. In the end, there’s a reason not a single public health agency in the world advises against drinking twice boiled water. Another factor in twice boiled water that may affect the flavour is higher concentration of impurities, which, as we already discussed, in realistic tea making scenarios isn’t actually going to be much different than once boiled water. Twice boiled water simply isn’t bad for you at all unless your particular water source was already bad for you at the once boiled level.