One cup of coffee can taste wildly different from another.
Many elements come together to determine the flavor and caffeine content of coffee. These include sourcing of the beans, the variety of the Coffea plant used, farming practices, and processing — including the degree of roasting.
Roasting involves heating pale green, spongy coffee seeds to transform them into recognizably brown, fragrant, and delicious beans.
Because dark roast coffee tends to taste stronger, you might wonder if it packs more caffeine than a lighter roast coffee.
This article explains everything you need to know about dark roast coffee, including its effects on your health and its caffeine content compared with lighter roasts.
Before reaching the brewing stage, coffee beans go through several processes that determine their flavor, caffeine content, and quality.
Roasting is just one of these steps. When heated to about 392–482°F (200–250°C), a green coffee seed darkens and expands. The darker the roast, the longer and hotter the roasting process (
- Light roast coffee: Beans are roasted at 350–400°F (177–204°C) for less than 10 minutes. The beans reach an internal temperature of 356–401°F (180–205°C). This yields a fruity, multilayered flavor and aroma (
- Medium roast coffee: The beans reach an internal temperature of 410–418°F (210–214°C). The heating temperature and time fall in between that of light and dark roasts (
- Dark roast coffee: Coffee beans are heated to an internal temperature of 465–480°F (240–249°C) at 400°F (204°C) heat for around 15 minutes (
Keep in mind that there are no standardized criteria for levels of roasting. While a pale bean likely isn’t anyone’s idea of a dark roast, the categorization can be relative to the roaster.
In the roasting process, several chemical reactions take place that alter the beans’ aroma and taste.
One of the most important of these is the Maillard reaction, describing the browning that occurs (
Darker roasts tend to pack a more intense flavor that has bloomed through the heating process. Associated notes include smokiness, deep chocolate, earth, spice, or wood. Lighter roasts, on the other hand, are often described as fruity, bright, crisp, citric, herbal, or floral.
Darker roasts are usually heavier-bodied, which describes how thickly the coffee coats your mouth. They also boast a bold aroma.
If you’re unsure of which coffee to choose, you can try a few brands and roasts to identify what suits your palate and caffeine preferences.
Unlike the flavor, aroma, and color of coffee beans, the caffeine content doesn’t concentrate or increase during roasting.
In fact, darker roasts generally have slightly less caffeine than their lighter counterparts. Medium roasts tend to fall somewhere in the middle. Still, any differences are negligible (
Instead, know that the caffeine content of a cup of coffee may rely more on the bean variety and the infusion or brewing process (
Weight vs. volume
Dark roast weighs less than lighter roast, as coffee beans lose mass and density during roasting (
If you’re comparing light and dark roast coffee by weight, the caffeine amount is comparable, with only a slightly higher caffeine amount in a lighter roast (
This is because you’ll wind up with a higher number of dark roast coffee beans to match the equivalent weight of lighter roast beans.
However, if you’re comparing light and dark roasts by volume — how much space the beans take up — a lighter roast will have slightly more caffeine (
This is because there is less caffeine per bean in a darker roast coffee. Also, because beans expand in the roasting process, there will be fewer dark-roast beans in a scoopful of coffee beans (
Either way, the difference in caffeine is not significant and shouldn’t be the determining factor when you’re choosing your next bag of beans.
Darker roasts typically boast a bolder, richer flavor and aroma than lighter ones. Coffee beans lose caffeine and mass in the roasting process, so darker roasts generally have slightly less caffeine, though the difference is negligible.
Coffee is a rich source of antioxidants and a boon to your health.
Dark roast coffee has all the same benefits as light and medium roasts. This includes proven benefits to mood, memory, metabolism, energy, and many others when consumed at up to 5–6 cups (1.2–1.4 liters) per day (
Plus, during roasting, late-stage Maillard browning reactions produce dietary melanoidins, a type of antioxidant that may help digestive health. Generally, melanoidins develop once raw beans are heated above 356°F (180°C), increasing slightly as the beans darken (
Still, more research is needed to learn more about the development of melanoidins and their antioxidant effects in humans.
The health benefits of light, medium, and dark roast coffee are comparable.
One downside of dark roasted coffee is the potential for a bitter taste, which can result either from the formation or loss of certain acids during roasting.
One review suggests that roasting decreases the content of chlorogenic acids, which are beneficial antioxidant-rich compounds. Still, this could be counteracted by the formation of melanoidin antioxidants as a result of the Maillard browning reaction (
Like lighter roasts, the more significant potential downsides of darker roasts center around caffeine intake. While coffee is a popular drink with many health benefits, imbibing too much caffeine at once or per day on a regular basis can have detrimental effects on your health.
These include anxiety, difficulty sleeping, irregular heartbeat, and digestive upset (
It’s generally safe to consume 400–600 mg of caffeine per day. However, this varies depending on your preferences, health, and genetics. This is the equivalent of about 4–6 standard 8-ounce (237-mL) cups of coffee (
Fatal overdoses have been reported in doses above 500 mg of caffeine at once –– the amount found in about 5 cups (1.2 liters) of coffee — though this is exceedingly rare (
To be safe, limit yourself to 200 mg at a time, found in around 2 cups (474 mL) of coffee. Or, stick to no more than 1.4 mg per pound (2.5 mg per kg) of body weight per day (
Those who are pregnant should consume no more than 200 mg per day, or about 1–2 average cups (237–474 mL) of coffee, according to the American College of Obstetricians and Gynecologists’ most recent 2010 recommendations (
People taking certain medications or who have migraine, high blood pressure, or heart disease should also be mindful of their caffeine intake (
A high caffeine intake can exacerbate these conditions. While caffeine response varies from person to person, those with migraine should limit their intake to no more than 200 mg of caffeine per day, or 1–2 cups (237-474 mL) of coffee.
A review of 34 studies found that 1.5–2 cups (356–474 mL) of coffee temporarily raised blood pressure an average of 8 mm Hg systolic and 6 mm Hg diastolic — the top and bottom readings (
However, there are no clear recommendations on how much caffeine people with high blood pressure or heart disease can have. Speak to a healthcare professional or registered dietitian for individual guidance (
If you’re looking to limit your caffeine intake but still want to enjoy coffee, darker roasts or diluting your coffee in filtered water may be a good way to go.
You can also try decaffeinated coffee. This variety still has a marginal 0–15 mg of caffeine per 8-ounce (237-mL) cup, but generally less than 5 mg. Because the caffeine content difference is negligible between dark or light roasts, let your preference guide you (
While coffee is generally regarded as safe, it’s a good idea to drink fewer than 6 cups a day, or even less if you’re pregnant or have certain health conditions.
Coffee quality can vary greatly. For example, the degree of roasting can change the sensory experience significantly. Unfortunately, learning how to buy a good dark roast may take some experimentation.
Roasting categories are not standardized and are mostly relative to the roaster. What one roaster thinks is a dark roast may equal what another roaster calls medium or light.
One thing to note is that a lighter roast bean will not have much oil on its surface. That’s because it hasn’t been heated to a point to draw these oils out. A darker roast bean, on the other hand, will appear a bit oily or shiny.
Sometimes the lingo within the industry can further the confusion. Here are some other names given to beans according to roast level, according to the National Coffee Association (28):
- Light roasts: Light City, Cinnamon, Half City
- Medium roast: American, City, Breakfast
- Medium-dark roast: Full City
- Dark roast: French, Italian, New Orleans, European, Viennese, High
Usually, dark roasts of poorer quality taste charred or burnt because of over roasting. This can overwhelm any other notes that might be inherent in the variety of the bean. Some coffee roasters may purposefully do this to mask older or poor mixes of beans.
When roasted well — enough to bring out chocolatey, smoky, or nutty notes, but not so much to burn the bean — dark roast coffee can be velvety and rich with a lingering finish.
Beans from Intelligentsia, Blue Bottle Coffee, Stumptown, Kicking Horse, Death Wish, Third Coast Coffee Roasting Company, and other artisanal roasters that value excellence are a good place to start or refine your journey.
While there are incredible blends out there, looking for dark roasts that use 100% Arabica beans is a safe bet to start with. These are the most common type of coffee beans on the market.
Another option is to buy your own coffee roaster and experiment with roasting times and temperatures yourself.
Dark roast coffee may be sold under other names, like Italian, French, Viennese, New Orleans, or European. To start, try 100% Arabica beans from a few brands to see what you like most — or buy a roaster and experiment yourself.
There are generally a few things to consider when choosing a coffee roast that’s right for you, including flavor and aroma.
The degree of roasting primarily impacts the mouthfeel and flavor of coffee, not so much the caffeine content. What significantly determines the caffeine content is the ratio of beans to water. In other words, how strong (concentrated) or mellow (diluted) your brew is.
If you’re looking for slightly less caffeine per cup and a bolder flavor, opt for a dark roast. Whether you brew this hot or cold should depend on your preference, keeping in mind that a cold brew has more caffeine prior to 1:1 dilution with filtered water (
Espresso — a form of coffee brewed with pressurized water that’s served as shots or as part of a mixed beverage — can range from 63–126 mg of caffeine per 1-ounce (30-mL) shot (
Sticking to single-shot beverages, whether alone or mixed with milk or water, can help you cut down on caffeine, too. Most espresso is made with darker roast coffee beans (
Other ways to cut down on caffeine include having a glass of water with your coffee, switching to green or black tea, or simply drinking a smaller portion.
Ultimately, feel free to taste different varieties and brewing methods to see what’s right for you.
A longer roasting time will mostly impact coffee’s flavor and aroma, and lesser so the caffeine content. If you’re looking to cut down on caffeine, you can always have a glass of water with your coffee — or simply drink less of it.
Roasting time and temperature impact the flavor — and to a lesser extent the caffeine content — of coffee beans.
While darker roasts boast a bolder flavor and a sometimes smokier aroma, they also have slightly lower weight and less caffeine.
However, the differences in caffeine are minimal. This is especially true if you are weighing out your coffee rather than comparing it by volume.
What and how you brew your daily cup of joe truly comes down to personal preference.
Just one thing
Try this today: Not sure which type of coffee to buy? Buy a sample of light and dark roasts and brew these the way you normally would. Before adding in anything else, have a sip of the light and then the dark roast coffee. Note the differences in taste and aroma and pick your favorite!