Well, Twinings has recently advised the best way to make a cuppa is NOT to have boiling water.
After choosing your perfect mug and tea combination the next step in the preparation is the water.
To make the most out of the tea flavours freshly drawn filtered water is the best way, Tea loves
oxygen as it helps the flavours develop. The more oxygen in the water the better tasting tea.

Once your water has boiled (Kettle or Boiling Tap) you need to leave this to cool. Pouring boiling
water over your tea is a no go, the main reason for this is that it will scald the tea leaves, therefore
stopping the tea from releasing all its maximum flavours. Tea is very delicate and needs to be
treated with respect.

Triflow’s Hybrid system has been designed with the tea connoisseur in mind, with fresh filtered
water feeding the boiling tank giving you the maximum oxygen in the water. Then when you draw
the Hot water from the tap it delivers a perfect tea making temperature of 98°C water straight into
your mug.
So, before you pour 100°C water over your next cuppa just have a re-think!

https://twinings.co.uk/blogs/news/how-to-make-a-cup-of-tea-perfectly