You're probably so used to drinking coffee in the morning that you don't even think about it. You're not thinking about the caffeine content in your coffee, you're not thinking about where it came from or what kind of bean it is or what it's doing to your body. You've never really felt the need to ask yourself these questions, because you know how coffee makes you feel and that's all that's mattered to you.
And while there's nothing wrong with listening to your body, if you're a huge coffee lover — which you probably are if you're an adult human on planet Earth — it wouldn't hurt to learn a little bit about something that basically runs your life. I mean, you'd be sleeping in, late for work, and totally unfocused if it weren't for coffee, so you might as well take some interest in what it's actually comprised of and how each different drink affects you differently, because they do. Not all caffeinated drinks are created equally. The stark contrast between the stats of many of your favorite drinks will definitely surprise you.
The Inertia took to their blog to break it down for us. Let's start with the misconceptions: espresso will boost you higher than coffee. Light roast is less potent than dark roast. Cold brew is stronger that hot coffee — all of those rumors are just that.
Espresso might have more caffeine per ounce, 45-75 milligrams, to a drip coffee that might only have 20 milligrams, but if you do the math, we have a lot more than one ounce when we're having drip coffee. So in total, a regular sized cup of drip coffee has far more caffeine than one shot of espresso. We're looking at 150-400 mg, depending on the size cup you order.
In terms of going for a lighter or darker roast, it's really more about the flavor than the caffeine level. Lighter roasts have more caffeine per scoop, but when both light and dark roasts are weighed for caffeine in a full serving the levels are about the same. So don't worry about the darker roasts being too strong, that's more of a sensual illusion than it is a fact. That said, there are tons of different types of coffee and each different species of coffee bean has different levels of caffeine. Seventy percent of the world's coffee comes from Arabica beans, but it's Robusta beans that have the most caffeine (nearly double what Arabica beans have).
While on a hot summer's day a cold brew might be the most appealing and refreshing option, the best way to extract caffeine from coffee beans is with heat. So whoever told you that cold brew has more caffeine than hot drip coffee was totally wrong. Taking all of this information and weaving it together, here's what you can deduce: if you want max caffeine, go for a double shot of Robusta coffee bean espresso. If you want an ice coffee, you'll have to order a larger size to get the same effect as a smaller hot coffee and you can get a light roast and a strong boost all in one drink.