Towering above the single-shot red-eye and the double-shot black-eye coffees, a dead-eye coffee is the strongest of the eye-themed coffees you can get with a whopping three shots of espresso added on top of a regular brew. Since espresso already contains more caffeine than normal coffee to begin with, you might be wondering how much stronger a dead-eye coffee actually is compared to your average cup. The answer may or may not come as a surprise: More than adequately living up to its name, a dead-eye contains an average of three times as much caffeine as regular coffee.
Of course, the math isn't precise due to various factors that affect caffeine content in espresso, so this is a rough estimate. If operating on the averages offered by the USDA, a single fluid ounce of brewed coffee has 12 milligrams of caffeine, whereas an ounce of espresso — the exact measurement for a standard shot — has 63.6 milligrams. Assuming that the standard cup of coffee is around six to eight ounces, that would mean a regular brew has around 72 to 96 milligrams of caffeine. Now, adding that to the total of 190.8 milligrams in three shots of espresso comes to 262.8 to 286.8 milligrams in a single dead-eye coffee. Depending on how much regular coffee you're adding the shots to, that's about three times — or even more — the caffeine of the original cup.
Why You Should Be Careful About Dead-Eye Coffees
While the impressive amount of caffeine concentrated into one dead-eye might sound appealing to those who need a stronger kick in the morning, you should really think twice before making a habit of ordering three extra shots in your coffee. According to the FDA, the maximum recommended daily amount of caffeine is 400 milligrams for an adult with no other relevant health conditions. You'll notice that the estimated 286 milligrams of caffeine in a dead-eye takes up the bulk of this recommended amount.
What makes things worse is that you can never accurately estimate how much caffeine you're getting in any single cup. Depending on the kind of beans, the quality of the machine, the darkness of the roast, and many other variables, every coffee shop will have different levels of caffeine in each shot that they pull as well as each cup that they brew. Starbucks, for example, is reported to have between 75 to 150 milligrams of caffeine in each fluid ounce of espresso depending on the source — that's a whopping 450 milligrams of caffeine in addition to the 235 milligrams of the Pike Place medium brew if you order a tall dead-eye from Starbucks.
While the FDA notes that caffeine poisoning only happens at 1,200 milligrams consumed rapidly, over 600 milligrams in one single cup is nothing to scoff at. A dead-eye coffee might be a powerful emergency pick-me-up in certain situations, but it's definitely something to be enjoyed in moderation.
Read the original article on Tasting Table.