How Much Caffeine Is In A Coffee Bean? (Expert Guide)

As someone who enjoys grinding my own beans and making coffee with a drip coffee maker at home, I've always wondered exactly how much caffeine is within a single bean.

Here, I've researched how much caffeine is within a bean - including whether the brew method can affect the caffeine levels if a decaffeinated coffee bean contains coffee, and more!

While there are a plethora of coffee plant species around the world, there are only two varieties that make up over 98% of the coffee grown worldwide.

These varieties are known as Arabica coffee and Robusta coffee, and I've compared the caffeine in coffee beans of these two varieties.

1. Caffeine In A Single Coffee Bean

On average, a single Arabica coffee bean contains 1.9 mg of caffeine, while a single Robusta coffee bean has nearly double with 2.9 mg of caffeine.

If you prefer stronger coffee, Robusta coffee is the way to go, as an individual coffee bean has more caffeine.

2. Caffeine In 1 Gram Coffee Beans

Per gram of coffee bean, you're looking at 1.2% caffeine or 12 mg of caffeine per gram for raw Arabic coffee beans. 

Robusta whole coffee beans, on the other hand, have 2.2% or 22 mg of caffeine.

3. Caffeine In 10 Grams Of Coffee Beans

There are about 120 mg of caffeine per 10 grams of raw Arabica beans and about 220 milligrams of caffeine per 10 grams of raw Robusta coffee beans.

For reference, there are about 76 beans in 10 grams of coffee - roughly equivalent to what I use for an average cup of coffee.

4. Caffeine In 15 Grams Of Coffee Beans

When it comes to the caffeine levels of 15 grams of coffee, there are 180 milligrams of caffeine for raw Arabica beans and 330 milligrams of caffeine for raw Robusta beans.

5. Caffeine In 20 Grams Of Coffee Beans

With 20 grams of beans, you're looking at about two cups of coffee brewed - though, of course, the brewing process will change the exact amount of caffeine in your coffee.

There would be 240 milligrams of caffeine in 20 grams of raw Arabica beans and 440 milligrams of caffeine in 20 grams of raw Robusta beans.

6. Caffeine In 25 Grams Of Coffee Beans

The amount of caffeine per 25 grams of beans is 300 milligrams for the Arabica type and 550 milligrams for the Robusta type.

7. Caffeine In 30 Grams Of Coffee Beans

30 grams will usually give me three cups of brewed coffee. You’re looking at 360 milligrams of caffeine for Arabica beans and 660 milligrams for Robusta beans.

Falling Coffee Beans

Brewing Alchemy That Shapes Coffee’s Caffeine Content

The brewing type can affect the caffeine in beans and, ultimately the caffeine level in a cup of coffee, as the amount of caffeine extracted is dependent on factors such as time, temperature, and the number of beans used.

How The Bean Is Roasted

Green coffee beans - aka beans that aren't roasted have a lesser amount of caffeine when brewed in comparison to roasted beans.

When it comes to the roast level (aka the roasting process), however, it doesn't actually have a huge impact on the caffeine content of the coffee.

During the coffee roasting process, the beans will undergo a series of chemical reactions that affect both the aroma and flavor but not the caffeine.

It's a common misconception, but I remember I used to think that dark-roasted coffee beans had more caffeine than a light-roast coffee bean![1]

Roasting time, however, will affect how much caffeine there is as it affects the mass of the coffee bean.

A longer roasting time will evaporate more water from the dark roast coffee beans - leaving it lighter and with less caffeine.

A shorter roasting time, on the other hand, will end up with beans that have a larger amount of caffeine as it doesn't lose as much water.

So, what that means is dark roast coffee beans have less caffeine while those with a light roast have more caffeine in coffee beans - who knew?

Pile of roasted coffee beans

It’s All In The Size Of The Grind

As someone that enjoys less caffeine in my coffee, I typically go for a larger coffee grind size.

If you're looking for that caffeine fix, you'd opt for finely ground coffee.

A smaller grind size has more caffeine as it has a more significant surface area-to-volume ratio.

Water Temperature When Brewing

The temperature of your water during brewing can also affect the caffeine level.

If you want a higher amount of caffeine, you're going to want to use hot water, about 195F to 205F. The hotter the water, the quicker it extracts caffeine, oils, and compounds.

Not all brewing methods are equal, though. I'm a cold-brew coffee fan. Cold brew is often known for having a higher caffeine content and stronger flavor.

It's not water temperature that is a factor here, but rather cold brew coffee contains a higher coffee-to-water ratio than instant coffee, lighter roasts, or even espresso.


Do Decaf Coffee Beans Contain Caffeine? (Surprising Truth!)

The simple answer to this is, yes, there's actually caffeine content in decaffeinated coffee beans.

I personally don't drink decaf coffee, but I know it's made with beans that have had at least 97% of the caffeine removed.

There is, however, still a certain level in coffee beans. As to how much, for a cup, you're looking at about 2mg - in comparison to a regular cup of brew coffee that has about 95mg.[2]

So, drink enough, and it can quickly add up to have a stimulating effect!

Hands Presenting Coffee Berries

Coffee Bean Caffeine FAQs

How much caffeine is in 1kg of coffee beans?

There are 12,000 grams of caffeine in 1kg of Arabica coffee beans and 22,000 grams of caffeine in 1kg of Robusta coffee beans.

Which coffee bean has the most caffeine?

Robusta beans have the highest caffeine content, with over twice the amount of caffeine you'd get from an Arabica coffee bean.

How much caffeine is in a chocolate covered coffee bean?

Depending on the brand, type of bean, and roasting method, a chocolate covered coffee bean contains between 2mg and 10mg of caffeine per bean on average.

How many chocolate-covered coffee beans is too much?

20 to 30 chocolate-covered coffee beans is the maximum per day if you're eating it directly, as that's about 300mg of caffeine in coffee beans.

How many coffee beans per drink?

The average cup of coffee takes about 70 beans per whole-bean coffee. It would differ, of course, if you're drinking specialty coffee or something different.


Conclusion

A Robusta bean has the highest amounts of caffeine in comparison to the Arabica bean, but it really varies depending on the brewing method.

The brewing process, for example, can affect how much caffeine is in that final cup of coffee.

Whether you use a French press or prefer Arabica filter coffee, I recommend experimenting with different methods to see how it changes the caffeine levels - you can even taste the difference!

References:

  1. https://www.scienceofcooking.com/caffeine-in-coffee-beans.html
  2. https://www.medicalnewstoday.com/articles/324986#caffeine-by-coffee 

Karmy Widjaja

Author

Karmy Widjaja
Karmy Widjaja, holding a degree in Hospitality Administration, combines her academic background with a profound passion for the world of coffee. Her work is enriched with a wealth of insights, not only about the art of coffee making but also about the broader aspects of the coffee industry. Her quest for coffee perfection is a central theme in her engaging articles, as she continues to explore the vibrant coffee scene in Perth. And when it's time for a coffee break? Karmy's all about a laid-back flat white with almond milk – it's her go-to for a tasty coffee kick.

My favorite drink? I'd go with... flat white with almond milk.

See Our Editorial Processes

Meet Our Team

Share Feedback

Leave a Comment