Why does tea steep faster in hot water than colder or room temperature water?

Question

I thought I turned the kettle on and came back but it wasn’t hot water and I tried to steep my tea and it barely steeped at all. But when the water is boiling hot, it steeps instantly. Why is that?

In: 7

Answer 1

There’s a rule of thumb in chemistry: for every 10 degrees Celsius reaction rates double. It’s not precisely true but it’s in the right ballpark for most things. It also applies to physical changes like dissolution. So going from ~20°c to 100°c would be 8 doublings or ~256x faster.
As to why it’s because the water molecules are moving faster. The stuff that dissolves is moved away from the tea leafs faster which lets more dissolve.