No one here is going to admit visiting a high street chain unless in the secrecy of the confessional but a Which report reckons cappuccinos at Costa have 325mg of caffeine while as we all would have known a Starbucks just 66 mgs. Other results Greggs 197, Prets 180,Cafe Nero 115 mgs. . Apparently a can of Red bull is 80 while Coca-Cola is 34.
With espresso, Prets 180 mg, Nero 45, Starbucks 33.
Filter coffee, Prets 271, Greggs 225, Starbucks 102.
A mug of instant is reported as being 100 (years ago I thought I read there was less caffeine in espresso than instant but when can you believe what you read).
Does taste relate at all to caffeine, I have no idea. When all my coffee was on expenses I thought Cafe Nero tasted stronger than Costa or Pret. It’s a rather flimsy test as the variations are in part due to the number of shots used in different outlets. Not sure they sent the coffee to the lab either, seems they just read what it said on menus and asked the chain to confirm.