There is no actual “caffeine meter”, which makes sense because I’m not an android, cyborg, or other advanced inorganic mechanism. However, I refer to “charging up the caffeine meter”, generally followed by a percentage, when I’m knowingly indulging in beverages which would probably do just that if I was a machine and did have a “caffeine meter”.
Over time, though, flavour does win out. Otherwise, I could find a strong and readily available source in most energy drinks, which I don’t touch unless I have a really late evening at a club to cope with.
Here are a few different go-to sources for me.
Ethiopian coffees. I could just say “specialty beans” but the overwhelming majority of specialty beans I ever buy are Yirgacheffe, Guji, and generally Ethiopian coffees. Can also include Arabica beans, if you want to widen the scope a bit further. What I could probably do is narrow down the list of coffees I can’t have, but then I would have to run into a lot of heat-inducing, sweat-inducing brews in the course of making a checklist. I prefer a conservative approach where I go to what I know works, and reach out for something new every once in a while. This is on the top end of price and I couldn’t possibly afford something this good every week, so it’s a once-in-a-while indulgence or treat.
Supermarket blends. Supermarkets with a selection of different coffee beans; this is for the inexpensive every-day home office brew. 50% of the bag will be filled with espresso beans, and the rest layered with different flavoured coffees, like vanilla, chocolate, Irish cream. Pour into the grinder, stir a bit to mix up the beans, and grind ’em all together. Brew like regular coffee. A bigger hit of caffeine than a regular cup, but with the added flavours and mixing, not quite as powerful as drinking a rather tall or grande espresso.
Discount bags. For when I really need coffee but I’m not at a place with a selection of beans or a grinder. Quite often the poorest tasting coffee I’ll ever have, but it does the job.