A new “Which?” study has revealed the “huge” differences in the amount of caffeine in coffees from leading high street chains like Costa, Starbucks and Pret A Manger. 

The findings show that a single espresso from Pret A Manger was found to contain six times as much caffeine as one from Starbucks. 

If you are more of a cappuccino lover, Greggs and Pret a Manger’s brews contain significantly less caffeine than one from Costa.

Coffee beans

The amount of caffeine varies depending on the Arabica beans, which contain around half the caffeine of Robusta beans. Variations can also be felt by consumers in taste between the beans’ varieties.

“I stick with soy mocha from Pret usually. For me, their coffee is the best. In moments where I can’t get Pret, I go to other chains with a heavy heart. I don’t have any preference for coffee beans. I mostly do decaf though.” said Pamela a coffee customer met on the street.

Giles Hilton, a freelance coffee and tea specialist, told Which? : ‘Light and medium roasted beans contain more caffeine than higher roasts, as the caffeine burns away as the roast level increases.’

As coffee can help people think straight and emerge in the morning but “our research shows you may be consuming significantly more, or less, caffeine than you bargained for” stated Which? nutritionist Shefalee Loth. 

Coming out of a Costa Coffee shop on blackfriars road, a customer named Pierre explained :

“I personally prefer Costa Coffee because the portion is not too big compared to Starbucks. The coffee tastes good because the barista grinds the espresso beans by himself and adds the espresso cream on the top, a significant factor of a good coffee.”

© Which? study figures

These differences bring up health concerns for caffeine-sensitive consumers such as pregnant women. The NHS explains pregnant women should consume no more than 200mg of caffeine per day. Therefore, depending on which coffee shops you fancy most, you could end up with long night-time insomnia.

As caffeine is a natural stimulant and like many things, it’s best enjoyed in moderation.