If you’re standing in line at your favorite coffee shop during your morning commute, trying to figure out which drink is going to hit you with the most caffeine possible, you might be inclined to go for an espresso (or any of the beverages made with it). After all, its dark, rich, concentrated flavor has to mean it has more caffeine, right? On an ounce-for-ounce basis, you’d be correct. Espresso has an estimated 63 milligrams of caffeine per ounce versus the 12 to 16 milligrams per ounce of coffee. But don’t worry, you can still order that iced latte. The true amount of caffeine you consume depends on how the coffee is brewed and the size of the drink.
Both drinks start with coffee beans, but different beans have different amounts of caffeine. Arabica beans, the most popular bean used for both espresso and coffee, contain about half the amount of caffeine as Robusta beans, the second most popular bean. The amount of caffeine changes once the beans are roasted and ground. That’s where the difference between coffee and espresso comes in. Espresso beans are roasted for longer and at a higher temperature than coffee beans. They also have a finer grind. Espresso is also brewed differently, using a hotter temperature and higher pressure. The brewing process helps extract the oils in the beans and gives espresso its unique, bitter taste –– helping it stand up against the foamed milk used for lattes and cappuccinos. It also means espresso is more concentrated than brewed coffee so there is more caffeine per ounce.
Other brewing techniques that affect caffeine concentration
Different brewing techniques are used for both coffee and espresso, which can also affect caffeine levels. For example, espresso can be ordered as a ristretto or a long shot. A ristretto uses less water and a shorter extraction time, while a long shot, also called a lungo, is made with the same amount of espresso but twice the amount of water. The higher concentration of espresso means the ristretto has more caffeine per volume.
Coffee brewing techniques can also have differing effects on the caffeine in your cup, depending on how much contact — and for how long — the water has with the grinds. A cold brew, which brews for hours, will have the highest concentration of caffeine. There are also differences between using a French press and a pour-over method, with the French press extracting more caffeine.
The most important thing to note is the size of your order. When you order an espresso, you’re usually served a single or double shot, with each containing one ounce of espresso (and therefore 63 milligrams of caffeine). Even in espresso-based drinks, you only get one to two shots. When you drink coffee, you’re more likely drinking at least 8 ounces –- the size of a short coffee at Starbucks — and getting about 95 milligrams of caffeine. But, be honest, how often do you order a short? If you order a medium-sized coffee — or a grande in Starbucks parlance — you’re likely getting 16 ounces of coffee and about 260 milligrams of caffeine if you’re getting a typical Starbucks dark roast, per the Center for Science in the Public Interest. That’s way more than you would get in that single espresso shot, so keep that in mind the next time you order your afternoon coffee.
