I Did Caffeine Analysis: Some Unexpected Results!

1 cup filter coffee can be 170mg or more. And LD50 isn’t really relevant here, even LD1 levels are deadly to hundreds of millions of people. It’s entirely possible for what some might consider a “normal” amount of coffee to be deadly to many. See other comment for espresso calculations. ▶ this video

Prep method matters so much though. For comparison, a standard double shot of espresso is typically 18g of coffee. This would yield approximately 110mg of caffeine. By comparison, the same 18g brewed using a pour over method should yield an 8oz cup of coffee with … likely around 170mg of caffeine. Check out this James Hoffmann video specifically on this topic: ▶ this video

Not necessarily true, filter extracts more caffeine than espresso at the same soluble extraction levels: ▶ this video The truth is there is not enough scientific research to compare all brewing methods. Espresso uses high pressure but very short brew times, but filter uses more water and longer brew times therefore the coffee comes out totally different, and that's before we even talk about different grind sizes and roast levels.