As someone who has spent over 20 years in the coffee industry, I often get asked how toasting affects the caffeinated content in coffee grains.
Key Takeaways of Does Roasting Coffee Beans Reduce Caffeine
- Roasting coffee grains does decrease the caffeinated content, but the reduction is fairly small. Light roasts retain more caffeine than dark roasts.
- Caffeine is stable at high temperatures, so most of it survives the toasting process. However, toasting does break down some of the caffeine molecules.
- The caffeinated content is primarily determined by the type of bean, not the toast level. Robusta beans naturally contain nearly twice as much caffeine as Arabica beans.
- Brewing time has a bigger impact on caffeinated content than toast level. The longer coffee is brewed, the more caffeine that is extracted from the grounds.
How Roasting Affects Caffeine Levels
Coffee beans start out green. They contain caffeine and numerous other compounds like chlorogenic acid. Roasting transforms the physical and chemical properties of the beans. The toasting process causes the beans to brown and develop more complex flavors and aromas.
But what effect does toasting have on the prized caffeinated content?
Roasting coffee does lead to some loss of caffeine. However, caffeine is very stable at high temperatures, so the reduction is quite small like when discovering the flavors of The Roasting Plant.
Studies show light roasts retain slightly more caffeine than dark roasts. However, the difference is only around 5-10% subject – caffeine reduction – object light vs dark roast.
For example, a typical 1 oz shot of espresso made from light roast beans may have around 60-65 mg of caffeine. The same volume made from dark roast beans would likely have 55-60 mg. So we’re only talking about a variation of 5-10 mg.
This minor change is not enough to make a noticeable impact on the “caffeine kick” you feel from the coffee.
Why Caffeine Is Lost During Roasting
The reason some caffeine is lost during toasting has to do with chemical changes in the beans.
When green coffee grains are roasted, the high heat breaks down some of the caffeine molecules (see green coffee beans for home roasting). The longer the beans roast, the more caffeine is degraded.
Light roasts spend less time toasting and reach lower peak temperatures compared to dark roasts. So there is less time for the caffeine to break down, resulting in slightly higher caffeine retention.
Additionally, toasting causes the beans to lose moisture. Caffeine is water-soluble. So the evaporation of water likely pulls small amounts of caffeine along with it.
Roast Level vs. Bean Type
While there is a slight difference in caffeinated content based on toast level, a much bigger determinant is the type of bean itself.
Robusta coffee grains naturally contain almost twice as much caffeine as Arabica beans – about 1.5-2.7% vs. 0.8-1.4%.
So if you want to maximize caffeine intake, drinking a light roast Arabica will provide less of a kick than a dark roast Robusta.
The reason for the discrepancy in caffeinated levels comes down to genetics. Robusta and Arabica come from different species of coffee plants. Through natural evolution, Robusta plants developed a higher caffeinated content, likely as a defense against pests and diseases.
Brewing Has a Bigger Impact than Roasting
In actuality, the way you brew the coffee has a much bigger influence on caffeinated levels than the toast level no matter what coffee roasting tips and tricks that you follow.
The key factors are:
- Brewing time – The longer the grounds are in contact with water, the more caffeine is extracted. Methods like cold brew and drip coffee yield more caffeine than espresso.
- Coffee-to-water ratio – Using more grounds per unit of water will result in higher caffeinated levels. Conventional brewing ratios are around 1:15 to 1:17 coffee to water.
- Grind size – Finer grinds lead to more efficient extraction and higher caffeinated content. Espresso is made from finely ground coffee.
- Bean weight – Obviously using more coffee grounds results in more caffeine per cup. The standard amount is 1-2 tablespoons of grounds per 6 oz cup.
So if you want to maximize the buzz from your morning cup, opt for a light roast, cold brew it for 12-24 hours, use plenty of finely ground coffee, and let the extraction do its work! If you’re interested in starting your own roasting business though, check out our coffee roasting business strategy guide now for launching your own coffee roasting business at home!
Frequently Asked Questions
While toasting does lead to some loss of caffeine, the reduction is quite small, only around 5-10%. Factors like brew method, grind size, and bean type play a much bigger role in determining caffeinated levels. So don’t be afraid to enjoy dark roasted coffee if that’s what you prefer! The key for maximizing caffeine is to cold brew or drip brew very finely ground beans for an extended time.
Here’s a quick meta description for this article: Roasting coffee grains does decrease caffeinated levels slightly, but the impact is minor. Factors like brew method and bean type have a bigger effect. Read on to learn how toasting affects caffeine.
I hope this article clearly explains how toasting impacts caffeine content and provides some useful tips for coffee lovers. With over 20 years in the industry, I’m happy to share my knowledge and experience about all things coffee! Let me know if you have any other questions.