A cup of coffee made with the following variables will have the most caffeine:
- Espresso brewing method
- Dark roast when measured by weight, light roast when measured by volume
- Robusta coffee beans
When combined, these 3 create an incredibly energizing cup of coffee that is sure to keep you going throughout a long and tough day.
Keep reading for details on each of the factors outlined above in terms of why they stand out among their competitors and the extent to which each factor impacts caffeine content.
Then at the end, we’ll recommend some excellent coffee beans for people looking to maximize their caffeine intake.
Maximizing Caffeine Content in Coffee: A Brief Overview
Answering the question of what coffee has the most caffeine is a little complicated because there is no one answer. Instead, there are 3 answers because the caffeine content of a cup of coffee depends on 3 independent factors. These are:
- Brewing technique
- Type of roast
- Bean variety
Espresso has the most caffeine content. The method uses high-pressure and superfine coffee grinds. This maximizes caffeine extraction from the coffee beans. You can get between 200 and 300 mg of caffeine in a 12-ounce cup easily.
When measured by weight, dark roast coffee beans have higher caffeine content than light roast.
The beans lose a lot of their moisture content and become lightweight. So you need a lot to make up whatever amount you’re looking for, which doesn’t happen with light roast beans.
Robusta beans have the highest caffeine content among coffee beans. They have 2x the caffeine than Arabica coffee beans – the most commonly used coffee bean. However, the bean’s bitter taste makes it unpopular in some circles.
You’ll have to try it to figure out if you like it.
Why the Espresso Brewing Method Maximizes Caffeine Content
While any particular coffee bean will always have a fixed amount of caffeine in it, the brewing method determines how much of that caffeine is extracted. Making an espresso extracts the most flavor and, consequently, caffeine.
There are 2 main explanations for this, and both refer to ways this brewing technique boosts the rate of extraction of flavor to make a strong cup of coffee. They are:
- The superfine grind size
- High pressure
An ounce of espresso has about 40 mg of caffeine. Assuming that an average cup of coffee has 8 ounces, you’ll get 320 mg. Given that the average cup of coffee has 100 mg of caffeine, this is a substantial amount.
Let’s take a look at both in detail.
Superfine Grind Size
Grind size is an important factor to consider when determining the strength or caffeine content in a drink. The smaller the grind is, the more easily it will dissolve into the hot water.
Since we’re usually dealing with almost powder-like coffee grinds when making espresso, it comes as no surprise that almost all the caffeine content in them gets extracted.
The scientific explanation behind this ease of dissolution is that the superfine grind size increases the surface area to volume ratio of coffee beans with water. At any given point in time, the solvent has access to more of the solute than it would have had if there were a few large grains instead of several small ones.
The high pressure speeds up gas particles and increases the number of effective collisions, increasing the rate at which caffeine is extracted from coffee beans.
Bear in mind that such agitation of the water can lead to a decrease in its temperature, so it’s crucial to moderate it and keep it at the ideal pressure.
Most baristas and coffee experts are able to do this, allowing them to make a strong caffeinated drink.
The dissolution process basically involves reactions between water and coffee grains. If they’re moving around and hitting each other at high speeds repeatedly, the probability of them reacting increases.
Think about how you can dissolve salt into the water quickly by stirring the container they’re in. The same principle applies there too.
The Caffeine Content in Other Brews
If you don’t have an espresso machine or appreciate the flavor of coffee made with one, you can try another brew. While it won’t have as much caffeine, it will still have a significant amount.
Here’s a list of all the main brew techniques in order of most caffeine content to least:
- Moka pot
- Electric dipper
- French press
- Manual drip coffee
The FDA says you shouldn’t consume more than 400 mg of caffeine a day. So if you plan to have more than one cup of coffee a day, it would be better if you considered going with a brew other than espresso.
While it does have the most caffeine, caffeine adds up. Even with just two 8-ounce cups, it is highly likely that you will end up going over the recommended limit. 2 cups of moka are a safer option. Or go with 3 cups of French Press.
Pick whatever works for you. Just remember to be safe when drinking your coffee.
Why Do Dark Roast Coffee Beans Have More Caffeine Per Gram
Dark roast coffee beans have more caffeine than light roast beans when you measure by weight. So a gram of dark roast will be more caffeinated than a gram of light roast.
However, light roasts might have more caffeine if you measure by volume through spoons or scoops. There is no way to tell without experimenting, so it’s a 50-50 chance for either roast having more caffeine.
Depending on what method you use, the answer to what kind of coffee is stronger will change.
How Roast Impacts Caffeine Content
High temperatures have no impact on caffeine itself.
However, they do reduce a coffee bean’s mass due to moisture loss. This increases the concentration of caffeine in each coffee bean which is why considering roast type is important if you want to be conscious about how much caffeine you’re consuming.
Dark roasts expose coffee beans to more heat than light roasts. While both will lead to the beans losing moisture, this impact will be felt more in the former.
Coffee beans tend to expand when exposed to heat. Dark roast beans will grow more than light roast beans. There isn’t a precise rate of growth or even a guarantee of growth.
This is why there is ambiguity when it comes to measuring coffee beans by volume. You can’t really know how much caffeine you’re getting because you can’t know how much the beans grew in size during the roast process.
Assuming they grow by a significant amount, the dark roast beans are light and big.
The light roast, on the other hand, is comparatively heavy and small. Each bean will have the same amount of caffeine but since measuring by the number of beans is impossible, you have to settle for weight or volume.
One bean of the dark roast will weigh less than one bean of light roast. So when you get a number of beans and weigh them, you’ll need more dark roast beans than light roast beans to make the same weight threshold. So you’ll be getting more caffeine.
Research shows that, on average, the difference in caffeine content for an 8-ounce cup of coffee made with light and dark roast beans is around 65 mg of caffeine. The light roast cup stands at around 170 mg of coffee, while the dark roast stands at 240 mg.
The specifics will change depending on what brewing method and coffee beans you use, but you can assume that there is around a 30% increase in caffeine content when you use dark roast beans instead of light roast.
What Makes Robusta Coffee Beans A Highly Caffeinated Variety
Coffea plant seeds are called coffee beans. Caffeine is a naturally occurring chemical in these seeds. Research shows that the robusta variety has more of it than other commercially grown varieties.
What You Should Know About Commercially Grown Bean Varieties
There are 2 main types of coffee beans: specialty and commodity. Commodity coffee beans are grown for commercial use. They’re cheap, mass-produced, and the ones used in coffee shops.
Robusta is a popular commodity coffee bean. It makes up 30% of the commercial market. The remaining amount primarily comes from a variety known as Arabica. It has less caffeine but a smoother flavor, making it easy to consume.
Robusta beans are low in acid content, high in sugar and lipid, and have a heavy flavor that a lot of people don’t particularly appreciate. This means that even though they have a lot of caffeine, people don’t like drinking coffee made with them very often.
Even so, you’ll find that robusta is commonly used in espresso blends and the production of instant coffee.
4 of the Most Caffeinated Coffee Beans
In addition to the brewing technique and roast, the type of coffee bean used also has a huge impact on the amount of caffeine in your drink.
Even if you can’t follow the other 2 tips for some reason, just using the right coffee beans will go a long way in strengthening your drink.
Here are some excellent coffee beans that have high caffeine levels:
- Black label by Devil Mountain
- Very strong coffee
- Black Insomnia Coffee
- Biohazard Coffee
Caffeine Content: 1500 mg of caffeine per 12-ounce serving
Bean Type: 100% Arabica
Despite the high caffeine content, these beans have a non-bitter flavor.
This can be credited to the use of Arabica grains. The coffee is non-gmo and certified to be organic. So there are no ethical concerns with consuming it.
The high caffeine content is no joke, so only get this if you are sure you can tolerate it. If you’re someone who doesn’t usually drink a lot of coffee but wants to try Black Label out because of the hype around it or because it is strong, take a step back and reconsider.
If you aren’t reading up on Black Label for the wrong reasons, though, you’re bound to love it.
The coffee smells great. It’s an amazing scent to wake up to if you’re lucky enough to have someone prepare a cup for you. Even if you don’t, it’s a great little thing to do for yourself. The drink will undoubtedly wake you up!
Caffeine Content: 1350 mg of caffeine per 12-ounce serving
Bean Type: 100% Robusta
Very Strong Coffee has a bitter taste and with the high caffeine content and Robusta beans, this shouldn’t come as a surprise. But it is bitter in a good way which is something you don’t come across a lot.
It has a rich and bold flavor. It also smells great, which is an excellent little bonus.
This is perfect for days when you can’t seem to get yourself out of bed. The coffee packs a punch and wakes you up in no time. But it does so with coffee that tastes and smells good. So you can’t really complain!
Caffeine Content: 1100 mg caffeine per 12-ounce serving
Bean Type: Arabica and Robusta blend
The black insomnia coffee is available in a bunch of different flavors, including caramel, macadamia, hazelnut, dark chocolate, etc. You’ll get the same baseline flavor of mild bitterness regardless of which one you pick.
It’s a great choice if you’re looking for moderately bitter coffee that packs a punch. This is one of the few high caffeine content coffees we found that use a blend of Arabica and Robusta. The rest used either one or the other.
So you’ll get an interesting experience if you choose to go with it.
Caffeine Content: 920 mg caffeine per 12-ounce serving
Bean Type: 100% single origin robusta
Biohazard coffee is made with Robusta grains, so one would expect a super bitter taste. Surprisingly though, it’s more earthy than bitter.
If you don’t particularly care about flavor, then this doesn’t matter. But if you do, you should know that you won’t be getting what you expect.
This isn’t to say that the coffee tastes bad. It’s just that it doesn’t taste like what a typical 100% robusta would do.
At the end of the day, you will definitely get a bunch of caffeine. So the rest shouldn’t matter very much. You can add flavorings like syrup or honey to improve the taste, and you’ll be good.
It has a lot of flavors, so you could just invest in them. You can get chocolate, nuts, tobacco, etc.
Which Coffee is the Strongest?
Black Label is the strongest coffee. Made with 100% Arabica beans, it has 1500 mg of caffeine in every 12-ounce serving. It has a bold flavor and an amazing smell.
Does Stronger Coffee have More Caffeine?
A stronger cup of coffee does not need to have more caffeine. Some coffee drinkers could define strength as the flavor, and then since high caffeine content drinks tend to be bitter, none of them would be defined as ‘strong.’
What Coffee Gives You the Most Energy?
Espresso coffee extracts the most caffeine from the coffee beans used. Since high caffeine coffee gives you energy, this is the kind of coffee you’re looking for.
Which Coffee Has the Most Caffeine Light or Dark?
Dark roasts have more caffeine. When measured by weight, a dark coffee roast will have close to 30% more caffeine than a light roast of the same beans.