Tea needs infusing for a specific length of time, and this can vary a great deal from one fine tea to another. A Japanese Gyokuro, for example, only needs infusing for a few seconds, while a white tea like Yin Zhen must steep for 10 minutes.
With some teas, like a Long Jing, for example, if you exceed the infusion time a little, it’s not a problem, and it won’t make much different to the final brew. However, if you leave a first flush Darjeeling for just a minute longer than you should, it’s quite simple: you’ll ruin it. It will become astringent and bitter.
So that’s why we need a timer when we prepare a good quality tea, and why we emphasise the importance of attention to detail with the infusion, to ensure you get the best from your tea.