Which UK Coffee Chain Serves the Strongest Coffee?

Coffee

4 Jun

Ever wondered why your morning coffee hits differently depending on where you buy it? The caffeine content in your cup can vary significantly between coffee chains. In this guide, we'll compare the caffeine levels in popular drinks from four major UK coffee chains to help you choose the brew that best suits your needs.

Caffeine Content Comparison Table

Here's a comparison of the caffeine content in a single espressos from various UK coffee chains:

Single Espresso caffeine content

  
      Coffee Chain
      Caffeine per Espresso (mg)
    
      Pret A Manger
      180 mg
    
      Tim Hortons UK
      125 mg
    
      Black Sheep Coffee
      125 mg
    
      Costa Coffee
      92 mg
    
      GAIL’s Bakery
      80 mg
    
      Caffè Nero
      80 mg
    
      Coffee#1
      80 mg
    
      200 Degrees
      80 mg
    
      Greggs
      75 mg
    
      McDonald’s UK
      71 mg
    
      Starbucks UK
      33 mg

Factors That Influence How Strong Your Coffee Really Is

Not all coffees are created equal, and we're not just talking about taste. Several behind-the-scenes factors determine how much of a caffeine punch your drink packs.

Bean Type Matters

The biggest caffeine culprit? The bean itself. Coffee beans come in two main varieties: Arabica and Robusta.

Arabica beans, used by most high street chains (including Pret, Starbucks, and Caffè Nero), have a smoother taste and less caffeine, typically around 1.2% caffeine by weight.
Robusta beans, commonly used in blends by Costa Coffee, have almost double the caffeine (around 2.2%) and a stronger, sometimes harsher flavour.

That’s why Costa’s cappuccinos regularly clock in with sky-high caffeine numbers, they’re blending for strength, not subtlety.

Roast Level

Here’s a fun fact to ruin a coffee snob’s day: Darker roasts actually contain slightly less caffeine than lighter roasts. That’s because the longer you roast a bean, the more caffeine degrades due to heat.

Light roasts tend to keep more of their caffeine content intact
Dark roasts, like those famously used by Starbucks, offer bolder flavour… but not necessarily a stronger kick

So while your taste buds might scream “strong!”, your central nervous system might respectfully disagree.

The Brewing Method

Even the fanciest bean won’t deliver a caffeine hit if it’s brewed poorly. Here’s what can boost or dilute caffeine extraction:

Grind size: Finer grinds = more surface area = stronger brew
Water temperature: Ideal range is 90–96°C; lower temps extract less caffeine
Brewing time: Longer contact = more caffeine. That’s why filter coffee and cold brew can pack a serious punch
Barista standards: Chains like Pret and Costa have standardised recipes (and generous espresso shots), while others may vary per location

So the caffeine content in your cup is as much about process as it is about bean pedigree.

Which Coffee Chain Caffeinates You The Most?

Let’s get to the good stuff.

Strongest Overall: Costa Coffee takes the title with a whopping 325mg in their medium cappuccino, the equivalent of three espressos in one foamy punch to the face.
Best Filter Coffee: Pret A Manger leads the filter game with 271mg per serving. If you want strength without the froth, Pret’s your pick.
Best for Caffeine Lightweights: Starbucks consistently ranks at the lower end of the scale, with smaller espresso shots and lower filter coffee numbers. Ideal for late-afternoon sipping (or anxious freelancers on deadline).

If you aren’t convinced by coffee chains caffeine content, why not make your own at home? We recently reviewed the strongest coffee in the UK.