It depends on the quality of leaves and style of preparation. The mental stimulation you get from black tea in a modern UK cafe is mild and very different from what you'd experience from Chinese Gong Fu Cha [0], or from Russian chifir [1]. Herbal infusions, which are still referred to as tea by many Americans and Europeans, will have almost no stimulant effect. It's quite likely that Boyle first drank tea in coffeehouses, where [2]:
> The whole of the day's tea would be brewed in the morning, taxed by a visiting excise officer, and then kept in barrels and reheated as necessary throughout the rest of the day.
If I was a coffeehouse owner, I would brew that tea for a long time to get as concentrated a drink out of it as possible.
> The whole of the day's tea would be brewed in the morning, taxed by a visiting excise officer, and then kept in barrels and reheated as necessary throughout the rest of the day.
If I was a coffeehouse owner, I would brew that tea for a long time to get as concentrated a drink out of it as possible.
[0] https://en.wikipedia.org/wiki/Gongfu_tea_ceremony
[1] https://en.wikipedia.org/wiki/Chifir
[2] https://www.tea.co.uk/a-social-history