Does Dark Roast Coffee Have More Caffeine?

Question

It is commonly believed that the dark roast coffee is much stronger and has more caffeine effect than the usual coffee. However, the truth remains that the dark roast coffee contains slightly less caffeine than lighter roasts. And the caffeine content actually depends on the time-frame that the beans are roasted, the more or the darker it is roasted, the less caffeine content it has due to the loss in moisture. (Via Times of India)

Comments

The claim that dark roast coffee has more caffeine than lighter roasts is a common misconception. In reality, the opposite is true, lighter roasts tend to contain slightly more caffeine than dark roasts. This is due to the roasting process, where beans lose moisture and expand as they are exposed to heat. The longer and darker the roast, the more moisture and caffeine content are reduced, resulting in a slightly lower caffeine concentration by volume for darker roasts.

It’s also worth knowing that while dark roasts have a bolder flavor and more intense taste, the roasting process doesn’t significantly change the total caffeine content when measured by weight. However, because dark-roasted beans are less dense, measuring coffee by volume (by scoops) would show a slightly lower caffeine amount compared to light-roast beans.

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I like the source that you used but are there any solid pieces of evidence within the article that made your claim true? Overall great job at finding information, but I'm just curious as to what you found, statistic wise.

Answer 1

Your overall claim that dark roast coffee doesn't have more caffeine than a lighter roast of coffee, is correct. But it's important to keep in mind that the difference in caffeine between light and dark-roasted coffee is so small it's insignificant and unnoticeable. Most of your explanation is correct. Caffeine content does actually depend on the time frame that the beans are roasted. However, it is important to mention that dark-roasted coffee does actually have more caffeine by weight volume. Here's a quote from an article explaining the math:

"Here’s how the math breaks down: Take 1000g of green coffee: it has about 12g of caffeine, or 1.2% of its total weight. Roast that coffee to a light roast, and the finished weight is around 850g. But there’s still roughly 12g of caffeine molecules in that roast, making the caffeine percentage 1.4% now. And if the coffee is roasted to a medium roast, the finished weight might be 800g, with still roughly 12g of caffeine inside, giving a caffeine volume of 1.5% of the total weight. Take a bean like a maragogype and roast it full dark, and the resulting 700g of coffee – which still has roughly 12g of caffeine inside – has 1.7% of its volume as caffeine.If we use 35g of roasted beans to brew 500ml of coffee, here’s how much caffeine, by weight, is stored in those 35g samples (noting that not all this caffeine will actually make it into your brewed cup of coffee):

Light Roast: .49g (490mg) of caffeine

Medium Roast: .52g (520mg) of caffeine

French Dark Roast: .6g (600mg) of caffeine"

Source: https://coffeegeek.com/blog/techniques/a-bit-about-caffeine/

The general consensus is that caffeine content in light and dark roasts depends on how you measure and brew your coffee not necessarily just the moisture levels. The difference in caffeine is negligible as long as the coffee beans are measured out by weight and not the volume of brewed coffee. 

Here are my other sources that back up this statement:

https://pmc.ncbi.nlm.nih.gov/articles/PMC8228209/

https://blackcreekcoffee.com/blogs/coffee-talk/which-coffee-has-more-caffeine-dark-or-light-roast

https://www.healthline.com/nutrition/light-vs-dark-roast-coffee#caffeine-contents

https://valor.coffee/blog/does-light-roast-coffee-really-have-more-caffeine-than-dark-roast

Comments

This was a really good fact check! you did a really good job breaking down the information and showing that the claim can be misleading! I really like that you included the sources you used too!

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This is one of the most thorough fact-checks I've ever seen and it is amazing. You used multiple sources, broke down information is an easy to understand method, and drew your own conclusions through the evidence provided.

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This is an insanely impressive fact check. You put a lot of effort into finding diverse sources as well as breaking down their information is thorough and easy to understand. You also did some math which I've never seen someone do on a fact check

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This is a really in-depth and thorough fact check. I liked how you used numbers and facts to prove your point and break down the information. I also liked how all the authors and websites you used for your fact check were credible and reliable sources. Again, how you used math to show evidence was unique and creative and really hammered your point down.

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This fact check was great at pointing out how there is little different between dark and light roast coffee. I especially like how you included the math and science behind each type of roast and their caffeine content/potency. The sources that were used are also credible, especially the one from the National Library of Medicine.