Which shade of coffee contains more caffeine? Here’s the short answer: it depends on a wide variety of factors but is definitely not due to the color.
Many people proudly declare that they drink only dark roasts due to their higher levels of caffeine. They have that idea because darker-roasted beans tend to have a stronger flavor. However, they’re wrong.
Others believe that light roasts actually contain more, as their view is that much of a bean’s caffeine is lost or burnt away during the roasting of the bean. That belief is also false.
The truth is that caffeine is exceedingly stable and unchanging when it is being roasted, and this is clearly proven by looking at the temperature coffee is roasted at. When roasting beans, temperatures almost never exceed 470 degrees Fahrenheit; yet, it takes heat over 600 degrees to actually affect the caffeine content in each bean. What actually affects the amount of caffeine in your coffee is the amount of coffee used during the brewing process.
Although the bean’s caffeine content changes little while roasting, a bean’s caffeine per volume and per weight shift substantially. The more time a bean is roasted, the darker, lighter, and larger it becomes.
The difference becomes more clear when one compares the two. Darker-roasted coffees, measured by volume, contain fewer coffee beans than a similarly-sized amount than their lighter-roasted counterparts–this leads to weaker flavor and less caffeine per cup than a comparable volume of the lighter beans.
However, when measured by weight, dark-roasted coffees actually result in a better-flavored and more caffeine coffee than their counterparts. Because of this outcome, many devoted coffee aficionados only measure their coffee by weight.
Take a certain weight of coffee beans, for instance, 25 grams. After you weigh each pile, look at the size of each group; you should find that the mass of dark-roasted beans is larger than the pile of light-roasted ones. The dark beans lose more water during roasting than their light-roasted counterparts, yet contain a similar amount of caffeine.
If you’re still confused, take an even smaller amount of beans- 10 or 15 grams. Put each shade in a pile, and count them. Most likely, there will be a couple more light-roasted beans than dark-roasted.
Now, this variation between the two may seem small, but think of how different the number of beans might be in an entire pound or two of coffee.
So, what should your conclusion be? Ultimately, your desired flavor will depend on many factors, including volume, weight, bean, and variety of coffee. Don’t stress out about getting every last bit of caffeine you can- the amount of caffeine in each cup of coffee is so small, you probably won’t even notice the difference.