The Allure of Caffeine
For countless people around the world, caffeine is an essential part of starting the day. For these individuals, grabbing a cup of coffee in the morning is right up there with brushing their teeth. What has caused this love affair between humans and caffeine? Interestingly, caffeine is actually poisonous if ingested in extremely high amounts. The amount of caffeine in a cup of coffee, however, is just enough to act as a stimulant to the central nervous system.
Effects of Consuming Caffeine
Consuming between 400 and 600 milligrams of caffeine daily is considered to be within the safe range and has no harmful side effects. In fact, research indicates that caffeine contains high amounts of antioxidants, particularly polyphenols and hydrocinnamic acids. Both of these antioxidants work to rid the body of free radicals and to prevent certain diseases, like type 2 diabetes and some cancers. In some individuals, however, caffeine produces unwanted side effects like trouble sleeping, heart palpitations, and anxiety.
How Much Caffeine Is in Coffee?
Several factors affect the caffeine content in coffee, including the specific type of bean and the way it was prepared. In short, the average cup of drip coffee has around 95 milligrams of caffeine, which is anywhere between 8 and 15 mg per ounce. Espresso, on the other hand, has between 30 and 50 mg per ounce.
This difference in caffeine content comes from the way the two coffees are prepared. Drip coffee, for example, is made by pouring boiling water over medium-ground coffee beans. The water then flows through the grounds and the filter, collecting in the pot below. The drip method produces a larger quantity of liquid. Espresso is prepared by sending a small amount of very hot water or steam through fine-ground coffee beans. The result is a smaller amount of liquid with a higher concentration of caffeine. People usually consume either a full 8-ounce cup of drip coffee or 1 shot of espresso, which means more caffeine is typically ingested with drip coffee.
Other Factors that Affect Caffeine Content
The way in which coffee is roasted is often considered an additional factor that affects caffeine content. Some research indicates that light roasted coffee has more caffeine than dark roast. This theory suggests that less roasting time prevents the caffeine from being broken down and allows more to make its way to the final cup of coffee. Other researchers argue that dark roast has more caffeine content because the longer roasting time results in the coffee bean being broken down, which allows more caffeine to be exposed and consumed. However, other researchers say that the difference between caffeine content in light and dark roasts is negligible.
Another factor that may contribute to the amount of caffeine in coffee is the amount of time it spends in contact with water. One of the slowest methods of brewing coffee is the cold brew method, which involves soaking coffee grounds in cold or room temperature water for 8 hours or longer. This method results in a type of concentrated coffee that in some cases has a higher caffeine content than either drip coffee or espresso. This concentration, however, is typically diluted with water or milk, thus reducing the amount of caffeine per serving size.