Not getting enough caffeine to jumpstart your day? If you're looking to understand and/or boost your morning coffee ritual, there are a few things to know about caffeine.
Arabica, which is the standard species of coffee plant, and far more prized as a source of quality coffee, typically has about 5 percent caffeine content. Among different arabica varietals, though, there are minor variations based on origin. Robusta beans, however, generally feature 2.4 percent caffeine. That said, robusta beans are generally known as tasting tar-like, which accounts for their use in low-quality, low-cost supermarket coffees.
Lighter roasted coffees have slightly more caffeine for two reasons. First, less roasting tends to preserve the compound untouched. The longer the roast, the more chemical transformation in the beans, including loss of caffeine. Second—and this is an odd point, because most of us measure our coffee by volume and not by weight when brewing—lighter roasted beans are denser, and therefore pack more bean per unit volume than darker roasts, which are far less dense.
Assuming you don't enjoy the taste of super-light roasted robusta beans, the best way to up your caffeine game is to think about how you brew (and how much you drink, of course). While espresso drinks have more caffeine per fluid ounce (80 milligrams in a 2-ounce serving), drip coffee has a standard unit of consumption (the "cup" versus the "shot") that's much greater (for example, a standard 12 ounce cup). So even though there's less caffeine in each ounce of brewed coffee, we generally end up drinking more of it.
Everyone has a unique metabolism, so the physiological effects of caffeine vary by person and their current caffeine habits and tolerance. (This is why some people can drink a cup of coffee and go back to bed). Caffeine absorption also varies by the contents of your stomach; specifically, fats like those from the milk you might add to your brew are known to inhibit caffeine absorption.
If you just want to up your caffeine consumption and skip the real complexities, we recommend simply drinking more coffee (by volume and variety).