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Does Dark Roast Coffee Have More Caffeine? (You’ll Be Surprised!)

dark roast coffee beans

When it comes to caffeine, coffee enthusiasts and daily coffee drinkers take their brew seriously. Millions head to their favorite coffee location for their morning or afternoon fix, relying on the stimulating effects of caffeine. While coffee, in general, has a lot of caffeine, there is some confusion on what roast has the most caffeine. The answer is both surprising and complex, but the general consensus is that light roast coffee has the most caffeine. But, as with most things in the coffee world, there’s a slight exception to that fact.

The Short Answer
Surprisingly, light roast coffee beans contain slightly more caffeine than dark roast beans — depending how you measure. Light roast beans have more caffeine by volume, while dark roast beans have more caffeine by weight.

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Caffeine and Coffee Roast

Why Does Light Roast Have More Caffeine than Dark Roast?

Light roast coffee generally contains more caffeine (by volume) than medium and dark roasts, which usually surprises people. It’s because light roast coffee spends the least amount of time in the coffee roaster, keeping a lot of the green coffee bean’s flavors, nutrients, and caffeine. The longer the bean is roasted, the less liquid remains inside it, making dark roast beans slightly lighter. However, it’s important to note that light roast has more caffeine per 6 oz serving. One small light roast coffee will not have more caffeine than a large iced dark roast coffee. 

cup of coffee
Image Credit: Raimond Klavins, Unsplash

What is Caffeine?

Although coffee enthusiasts mostly drink coffee for the flavor profiles and taste, many people flock to their local coffee shops to get their daily caffeine fix. The reason coffee is so popular is due to caffeine, a type of stimulant that is both legal and widely available around the world.

It works by agitating the central nervous system, increasing brain activity, and triggering chemicals like adrenaline. Caffeine gives the user more energy and alertness, similar to the fight-or-flight response. Because of the effects that caffeine causes, many people have a cup of coffee to help them wake up and start the day.

Caffeine is helpful for many people, but it does come with caveats. For one, it’s a highly addictive stimulant and can be quite difficult to quit. It also has quite a few side effects that can lead to unpleasant conditions like insomnia, anxiety, heart palpitations, and jitters.

Is the Caffeine in Coffee Natural?

Yes! The caffeine in coffee is completely natural. Caffeine is in many plants and natural sources, from cacao plants to various tea leaves. Caffeine in pills, energy drinks, and sodas are usually from artificial sources and are generally bad for your health. Some studies show that coffee could be beneficial for your health and wellbeing, even though it contains caffeine.

Caffeine is also in a few types of tea, though it reacts with the body differently than the caffeine in coffee. The presence of polyphenols is responsible for that, which helps restrict the absorption of caffeine in the bloodstream. They’re the reason why caffeine from tea feels different than caffeine from coffee, which hits the bloodstream much stronger and at a faster rate.

barista with fresh black coffee ready for customer
Image Credit: Ketut Subiyanto, Pexels

How is Caffeine Measured in Coffee?

This is the trickiest part of understanding coffee roasts and caffeine content: light roast coffee will have more caffeine per scoop but not weighed out on a scale. Light roast coffee will lose the battle to dark roast by weight, for a few reasons. Since most people use a scoop to measure their coffee, a light roast is considered to have more caffeine. However, it’s important to note that caffeine levels change only a small amount between roasts, so you might not even feel the difference between a light roast or dark roast caffeine buzz.

When coffee beans are roasting, they lose water throughout the roasting time, and their density changes. Since coffee beans swell in size as they roast, light-roasted coffee beans will be smaller. That means more beans per scoop, giving you more caffeine per scoop.

Coffee beans lose their density and weigh less as they roast, though, and that’s where things get complicated. That means dark-roasted coffee beans will weigh less than light roasts. If you measure your coffee bean scoops by weight, you’ll have more dark roast beans and technically more caffeine.

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Types of Coffee Roasts

Light Roast

The one that, by the scoop, packs the most caffeinated punch, light roast coffee spends the least amount of time in the coffee roaster. It contains most of the original coffee beans’ flavor notes and nutrients, little to no oils on the beans, and high acidity. Brewed light-roast coffee is light and “blonde” in color and smoother to drink than medium and dark roasts. It also has no body, which is in stark contrast to the heavy body of dark roasts.

Medium Roast

Medium roast coffee is what most people think of when they think of coffee. The beans are reddish-brown in color than light roast and a minute coating of oils, with some caramel and darker notes shining through. It’s a little more bitter than light roast, but with less acidity and more body. It’s truly a middle-ground roast and a great place to start for new coffee drinkers.

coffee beans roasting in a metal equipment
Image Credit: Maria Orlova, Pexels

Dark Roast

Full of body and covered in oils, dark roast coffee beans are a dark brown in color and have a stronger “roasted” scent. Dark roast is more bitter than medium and light roast, with strong earth and caramel notes due to the longer roasting times. Dark roast is extremely popular for iced coffee, cold brewing, and for those who simply enjoy the deeper, bolder flavors.

French/Espresso Roasts

Espresso and French roast coffee beans are slick and covered in oils, almost jet black in color with a burnt smell like a campfire. Espresso roasts need to be dark to make drinks with an espresso base, such as lattes, cappuccinos, and macchiatos. French roasts are not as dark as espresso roasts, but they are still quite dark and bold in flavor. They’re also great for cold brew, which will help lessen the intensity of the bitterness. 

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Coffee Quality and Other Factors

Does the Brewing Method Influence the Amount of Caffeine?

Coffee brewing is a science and an art, often changing the flavors and strength of the coffee. Drip-brew coffee will always be more acidic than cold brew, for example. While most brewing methods will usually retain a similar amount of caffeine per cup, the amount of caffeine will depend on a couple of factors: how many scoops you use and the quality of your coffee maker or brewing machine.

Low-Quality vs High-Quality Coffee

When it comes to coffee quality, fresh, high-quality coffee will always have better flavors and tastes. However, the caffeine content won’t disappear with time, even if coffee is of cheap, store-brand quality. Also, coffee that is stale and bland may seem like it’ll be weak, but it will still have the same amount of caffeine since it doesn’t evaporate.

drip-brew coffee
Image Credit: Emma Smith, Unsplash

Coffee Maker Quality

The quality of your coffee maker is important for coffee flavor and caffeine content, for a couple of reasons. For one, if your coffee maker doesn’t reach peak temperature (~195F), the coffee won’t brew correctly, and you’ll have weak coffee as a result. It’s crucial to invest in a good coffee maker, but you don’t have to spend hundreds on a premium machine.

Another issue is with hard water and minerals, which can cause a buildup in your machine. This can also lead to weak coffee, which possibly means less caffeine in your cup. Descale your machine and clean it out routinely, especially if you live in a region prone to hard water. Keurig coffee machines seem especially prone to this, so descale it at least every three months.

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The age-old battle between light roast and dark roast coffee has been debated for quite some time, but the answer is a bit complicated and depends on perspective. Because dark roast coffee has more caffeine by weight and not by scoop, many claim that light roast has more caffeine because people are more likely to use a scoop to measure their coffee. Although light roast coffee technically has more caffeine than a dark roast, the actual amount is fairly negligible if you’re looking for a serious caffeine boost. Still, it’s a good idea to give the light roast a try if you’re a dark roast drinker and see if it gives you a stronger caffeine buzz.

Featured Image Credit: Adam Nieścioruk, Unsplash


Jaimie Wisniowski

Jaimie is a freelance writer fueled by coffee, whether it’s hot, iced, or made from a local coffee shop. She enjoys writing all things coffee, especially if it means trying the latest coffee shop trends (hello cold foam!). After spending years writing poems, college essays, and short stories, it only a matter of time to turn writing into a career. Writing about coffee simply combined two of her favorite things! When she’s not drinking coffee by the minute and writing at her laptop, Jaimie spends time hiking, exercising, and living an active life. She also loves to snuggle up with a good book and her dog, Margo. If you catch her without a cup of coffee, she’s probably on her way to the coffee maker now.

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