If you've ever assumed the darker the roast the stronger the caffeine hit, you're definitely not alone. Many coffee drinkers believe that a darker bean means a bolder, more intense hit of caffeine. But is that really the case? Strap in as we are going to debunk this myth once and for all.
What Does "Strength" in Coffee Really Mean?
Before we dive into caffeine content, we need to clarify what "strength" actually means in coffee terms. We have our Strong AF coffee which we like to say is "roasted to death" but it doesn’t mean strength of the caffeine levels but the bold nutty and chocolatey favours. Many people associate dark roasts with higher caffeine strength because of their punchy, intense, deeper and smoky flavours. However, strength in coffee is more about the ratio of coffee to water in a brew rather than the roast level itself.
In other words, when we mean strong we mean the flavour punch rather then the caffeine kick.
So Come On Then Do Darker Roasts Have More Caffeine?
The short answer: no but it is interesting why:
Caffeine Is Stable During Roasting
Caffeine is a highly stable alkaloid compound with a melting point of approximately 238°C (460°F). Since standard coffee roasting temperatures range between 180°C (356°F) and 230°C (446°F), caffeine remains largely unaffected by the process. Research published in the Journal of Agricultural and Food Chemistry confirms that caffeine degradation only begins to occur at extreme temperatures well beyond standard roasting conditions.
Lighter Roasts Can Actually Be More Caffeinated by Weight
Studies of caffeine content in light vs. dark roasts have found that, per gram, light roast beans tend to contain marginally more caffeine.
Since coffee beans lose moisture and mass during roasting, dark-roasted beans are less dense than light-roasted beans. This means that if you measure your coffee by weight (e.g. 17 grams of beans for your espresso brew), you’ll get more individual light roast beans in that weight, leading to slightly higher caffeine content compared to an equivalent weight of dark roast.
I want more caffeine in my cup, what do I do?
If you are still craving more caffeine to get you through another rough Monday how can you get more of it in your veins then?
Well, the International Journal of Food Sciences and Nutrition says that the primary factors affecting caffeine extraction are grind size, brewing method, and coffee-to-water ratio, rather than the roast level itself. So instead of focusing on roast level, consider brewing method and coffee-to-water ratio. But what does that look like in practice?
1. Adjusting Coffee-to-Water Ratio
Using more ground coffee per unit of water increases caffeine concentration. A typical brewing ratio is 1:16 (1 gram of coffee per 16 grams of water), but reducing the water amount or increasing the coffee dose results in a stronger and more caffeinated cup.
2. Using a Finer Grind Size
A finer grind increases the surface area exposed to water, allowing for more efficient caffeine extraction. This is why espresso, which uses a very fine grind, has higher caffeine concentration per ml compared to coarser methods like a cafetière.
3. Brewing for a Longer Extraction Time
Longer brewing times allow for greater caffeine extraction. Cold brew, which steeps coffee grounds in water for 12-24 hours, typically has a higher caffeine content than standard drip coffee.
4. Opting for a High-Caffeine Coffee Variety
Arabica beans are known for their smooth flavour but contain less caffeine than Robusta beans. Choosing Robusta-based coffee blends or single-origin Robusta beans can significantly increase caffeine intake.
5. Drinking Larger Servings
A single espresso shot has around 63 mg of caffeine, but a full 12-ounce cup of drip coffee can contain 120-200 mg. Simply drinking a larger portion increases total caffeine consumption but we hope you already knew that…right?
Final Sip ☕️
Dark roast coffee doesn’t necessarily have more caffeine—it just tastes bolder and deeper. The real strength of your coffee depends on how you brew it and how much coffee you actually use. So, whether you love the smoky richness of a darker roast or the bright acidity of a light roast, the choice should be about flavour preference, not caffeine content, so go with what tastes best to you—not just what you think will keep you awake longer! If you are struggling with what coffee to try based on this news then take our quick quiz and you’ll be getting the right caffeine fix in no time.
