Tea or caffeine??

So Let's start by clarifying a bit: let's begin by saying that teina does not exist; or rather it is used as a synonym for caffeine. So if we want to be correct and a bit picky, we must say that tea does not contain theine but caffeine. It seems quite clear as a concept, right? Caffeine, as everyone knows, is an active ingredient like many others found in plants. Let's say that this active ingredient is found in not many plants: coffee, tea, guayusa, yerba mate, and some other medicinal herbs, but in very low quantities. The plants that have the most are coffee (as many may have guessed) and also guayusa, which is no joke. As for tea, the situation is very variable because it depends a lot on the type of tea and especially on its processing methods. It is not always true that black tea, for example, has more caffeine than green tea, or it is not always true that white tea does not have any, and so on. A lot also depends on us: how many leaves we put in the infusion and how long we let them steep in the cup. Without going into too much detail, I would like to mention a couple of key principles on the subject. One is the one mentioned earlier, another one I wanted to share is this: contrary to popular belief, there is more caffeine in the youngest leaves than in the larger ones. So the apical buds with the first leaf are the ones with the most active ingredient. This is because the plant uses caffeine as a repellent for insects and clearly concentrates it more in the newborns... cool, right? Another rule is that among the processing methods, leaf roasting is definitely one that causes the most caffeine loss in the leaves, so many Japanese teas like kukicha or bancha actually have little caffeine. The same goes for oolong teas, whose process of light roasting and semi-fermentation actively contributes to the loss of caffeine.