Dark Roasts vs. Light Roasts
Word has it, everyone's saying it, and the masses believe it. Light roasted coffee has more caffeine! But what are "they" basing the caffeine analysis on? Science, or myth...
The truth is that caffeine is extremely stable during the roasting process.
Even though the individual beans go through physical and chemical changes while it’s roasted, the amount of caffeine a bean starts with is generally the amount it ends up with. If you’re talking about individual beans, the caffeine level is the same whether it is light or dark roasted.
According to an in depth study by Juliet Han, in her published research paper "Correlation Between Caffeine and Roast Levels Using HPLC" there is evidence to prove that dark roast, by weight, contains slightly more caffeine than light roast.
My laymen explanation goes like this.... You've probably heard the fat vs. muscle analogy. You know the one that goes "Muscle weight more than fat" but in truth, five pounds of fat is simply larger (volume / takes up more space) than five pounds of muscle. Same with light coffee and dark coffee. Dark coffee is lighter in weight than light roasted coffee because it expands more in the roasting process. The beans are bigger (let's say they're fluffy or fat). Therefore, if you measure one scoop of dark roasted coffee and the same one scoop of light roasted coffee, you will actually have slightly LESS coffee grounds (by weight) in your scoop containing the dark roasted coffee. You'll have more light roasted granules in the scoop. More granules = more caffeine. This is why the best method for brewing coffee properly is by weight, not volume. It's ok to scoop, but just use a heaping scoop when brewing a dark roast.
So it’s not necessarily that “dark roast has more caffeine”— caffeine is stable across roasts, but rather, dark roast is less dense. The difference mostly boils down to density.
Here's a video to demonstrate this: YOUTUBE (don't forget to subscribe!)
So, how does this change a cup of coffee?
When you make a 12 ounce cup of coffee, and weigh out 22 grams of ground coffee, you have to use more (volume) dark roasted beans (because they weigh less) than you do when using a denser, light roasted coffee. This means you will get a similar level of caffeine when making a cup of dark coffee as you do with light roasted coffee.
Yet, why do you get more of a caffeine buzz when you drink light roast then... what's going on here? Who's right and who's wrong...
You are most likely measuring your coffee by scoops, and light roasted coffee will have slightly more caffeine because you will be using more light roasted coffee grounds when you're scooping vs. weighing. More coffee grounds = more caffeine.
What should also be noted is that beans vary in levels of caffeine depending on the plant species. Robusta beans contain more caffeine than the Arabica species. So depending on what type of coffee beans you buy and how you measure your coffee grounds (volume or weight), you can get different results each time. So your final answer? It depends :-)
To get the best-tasting coffee, consider trying Air Roasted coffee beans from Bean Hoppers. We use 100% specialty grade Arabica beans and ship within 24 hours of roasting.
Air roasting unleashes the coffees flavors and creates a smoother cup of coffee. Always delicious! Guaranteed.