There is no realistic scenario where, no matter your extractions or bean selections, 6-10 shots of espresso a day is not an enormous amount of caffeine
There is no realistic scenario where, no matter your extractions or bean selections, 6-10 shots of espresso a day is not an enormous amount of caffeine
A grande americano at Starbucks is a 16 oz drink with three shots of espresso. Have one in the morning and one in the afternoon and you are at six shots of espresso. That doesn't seem all that enormous to me.
75mg per shot = 450mg caffeine
That's a bit over the recommended limit of 400mg a day the Mayo Clinic, FDA, etc. recommend. Not sure it it qualifies as 'enormous' or not.
The amount of caffeine that humans require to live is 0 mg. So ...
Irrelevant to the question (How much is 'enormous'?).