How would the Roasting Time of Coffee Beans affect their Caffeine Content?

How would the Roasting Time of Coffee Beans affect their Caffeine Content?


If you are a coffee lover then you must have heard that the caffeine content is affected by the roasting process of the coffee beans. But do you know why this happens? Or, you may be also not sure whether there is any relation between the roasting time and the caffeine content of the beans. Even if you know, you may have learned from your peers that lighter roasting of the coffee beans implies a higher amount of caffeine content.

This is not at all correct and it can make you feel that the roasting process is complex. That is why we are here to make you aware of the fact that ‘How would the roasting time of coffee beans affect their caffeine content?’

Before directly diving into the factors that affect the caffeine content, let us take a tour through the various types of roasted coffee beans that you can find in the market.

Different types of coffee bean roasts –

We hope that you have heard of ‘light roast’, ‘medium roast’, and ‘dark roast.’ And, also you purchase the type of roast that you have tasted once and prefer the most. Some of the coffee bean manufacturers also use different names to describe the roasting type while the most common way is by categorizing them by their color.

As we mentioned that color of the coffee beans is the most common type of categorization, let’s see the difference between these three roasts concerning that.

  • The lightly roasted coffee beans are recognized by their light brown color and roasted at temperatures around 200-degrees Celsius.
  • For medium roasting, the brown color becomes slightly deeper than the light roast and the temperatures range above 200 to 220-degrees Celsius.
  • Then the dark roasted coffee beans are almost black or more specifically, darker brown. The temperatures required for dark roasting are nearly 240-degree Celsius and the surface of the coffee beans becomes shiny due to the extraction of the oil from inside.

Let us move on to the main focus of this article which is whether the roasting time affects the caffeine content of the coffee beans.

How would the Roasting Time of Coffee Beans affect their Caffeine Content?

When coffee beans are being extracted from the fruits (known as cherry), it is referred to as green coffee. You can consume coffee with those as well but the most commonly available ones are the roasted coffee beans.

As the roasting process of the coffee beans is carried on, the chemical composition, as well as the physical composition of the coffee beans changes like the color, becomes darker as long as you roast them, and more.

This is what people notice and classifies them accordingly as we explained in the previous section. In most of the coffee forums that we have gone through, we have seen that they mentioned that a reduction in the caffeine content is a result of the heat generated during the roasting process. Sometimes, they also specify that white coffee consists of more caffeine content than the other types.

All these things have soiled a myth in people’s minds that the type or degree of roasting is inversely proportional to the caffeine content of the coffee beans like the lighter roasts have more caffeine than the darker ones. But let me tell you the fact which is that the caffeine content remains the same during the roasting process.

This truth may have shocked you and created another doubt that then why do people say that roasting time affects the caffeine content! Let us provide you a detailed explanation in this regard.

We have mentioned earlier that the roasting process varies the physical and chemical composition, right? So for that reason, the coffee beans lose some amount of moisture that makes the beans dry and expand. Hence, you can very well understand that the mass of the coffee beans is losing with the increase in volume.

So, it is somewhat true that the amount of caffeine content varies but it is not the roast type that causes the difference in the caffeine content rather the method of measuring the coffee beans. We know that you are not getting it, don’t worry; your confusion will be cleared in the next paragraph only.

Say, you are measuring the coffee beans by scoops, then the lighter roasted ones will have more caffeine content than the dark roast beans because the former types are denser than the latter type. On the other hand, by weighing the coffee beans, darker roasted beans will have more caffeine content due to lower mass.

We are pretty sure that you have got it now, hence let’s check out some other factors affecting the caffeine content.

Other Factors affecting the caffeine content –

Composition of the coffee beans: Generally, the coffee beans’ composition can be found in two forms – Arabica and Robusta. However, Arabica is more popular than Robusta but Robusta contains a higher amount of caffeine content than Arabica.

Brewing Time: The brewing methods in which the coffee will be in contact with water for a longer period, the beverages produced will contain higher caffeine content. With the brewing time being more, the caffeine content will also increase. However, within the first minute of brewing, almost 90% of the caffeine gets released so expanding the brewing time can spoil the flavor of your coffee a-overall.

Amount of coffee beans added: If you add more amounts of coffee beans either by mistake or intentionally, then your coffee will result in a higher amount of caffeine content though this can also result in your coffee having a stronger flavor.

Apart from these three major factors, the grind size, temperature of brewing also has impacts on the caffeine content of the coffee beans.

The Final Takeaway…

We hope that you have understood what we have explained in this guide. The roasting time has an impact on the final coffee that you are drinking but not on the caffeine content. Hence, there is a difference in the caffeine content between different coffee bean roasts but that does not have anything to do with the roasting time rather it is the way of measuring the coffee beans.

Thank you, let’s meet in our next reviews or guides soon!


A coffee enthusiast from Asia keeps trying new hot beverages and sharing all his experiences with the internet. Aayush is a writer by profession who only thinks about coffee. He loves to brew and create unique recipes and share them with the public. Aayush had tried different types of coffee from different sides of the world. His favorite coffee is the Hawaiin Kona Coffee.

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