How the Beans, Brewing Method, and Grind Impact the Amount of Caffeine in Your Coffee

If you drink a cup (or two) of coffee every morning, you might wonder how much caffeine you are consuming. Before you pour another mug and add some cream and sugar, here’s what you need to know.

According to the U.S. Food and Drug Administration, an eight-ounce cup of coffee contains between 80 to 100 milligrams of caffeine. By comparison, a 12-ounce can of soda typically contains 30 to 40 mg of caffeine. And most major energy drinks contain between 70 and 100 mg of caffeine. But how much caffeine is too much? Health experts say that most healthy adults can safely consume between 300 and 400 milligrams of caffeine per day (or about three to four eight-ounce mugs). That means you’ll get all of the good side effects of caffeine consumption — namely, increased alertness — without any of the bad. Too much caffeine consumption, however, may temporarily lead to severe health concerns such as anxiety, nausea, headache, and an increased heart rate.

But this is just an estimate of the amount of caffeine in a cup of coffee. Factors such as the type of coffee beans, the specific brewing method, the ratio of grounds to water, the size of the grounds, and how long the grounds steep in water will all impact exactly how many milligrams of caffeine are in your cup. Here are a few things to keep in mind.

As a rule of thumb, light roast coffee contains more caffeine than dark roast, despite the latter’s bolder flavor. Generally, coffee brewed with finely ground beans will have higher levels of caffeine because there’s a larger surface area that’s exposed to the water during brewing. Plus, it takes more time for the water to work through the grounds, resulting in a more concentrated cup. The brewing method also has an impact. A Moka Pot produces a stronger cup than traditional drip coffee makers. Pour-over and drip coffee methods fall somewhere in the middle. 

Breaking down the beans

So which types of coffee have the most caffeine? Turkish coffee and espresso will perk you up the most, as both are made with very fine coffee grounds. A two-ounce cup of Turkish coffee, which is the typical serving size, contains approximately 50 milligrams of caffeine. On the opposite end, any style of coffee made with coarse grounds such as French press and cold brew coffee won’t be as strong because water passes through the grounds more quickly.

Espresso

If you’re looking for a quick pick-me-up from one of your local coffee shops, you might wonder if a shot of espresso contains more caffeine than an eight-ounce cup of coffee. A one-ounce shot of espresso contains between 40 and 60 milligrams of caffeine; again, the exact amount depends on the type of beans used and how they were brewed. This means that a latte brewed with two shots of espresso contains roughly the same amount of caffeine as a small eight-ounce coffee. However, you’ll get a bigger boost if you go for a medium or large cup of coffee. For example, a Starbucks venti beverage contains 24 ounces of coffee, which means you’ll be sipping up to 400 milligrams of caffeine (and potentially more if you go for their lightest roast).

Decaf coffee

Don’t let the name fool you. Decaf coffee isn’t completely caffeine-free. According to the National Coffee Association, approximately 97% of caffeine is removed from the beans, meaning that an eight-ounce cup of decaf only has about two milligrams of caffeine. Decaf coffee is a great option for anyone who is trying to limit their caffeine intake but wants to enjoy the ritual of drinking coffee. Looking to lower your intake of caffeine overall? Health experts at Princeton University recommend taking note of how much caffeine you typically drink (it might be more than you realize!) and blend regular coffee with decaf coffee to slowly but surely reduce your consumption.