Does roasting affect the caffeine content of coffee?

DOES THE CAFFEINE CONTENT CHANGE DURING ROASTING?

Caffeine is relatively thermally stable, its melting point is as low as 235℃, a temperature that is never reached during roasting as it would degrade the whole bean. Thus, the temperature during roasting has no effect on the loss or gain of caffeine. However, the caffeine content may increase slightly due to sublimation, the evaporation of water. Thus, the total volume of caffeine in a batch does not change, only the ratio in relation to the amount of other substances.

DOES THE SIZE OR WEIGHT OF THE BEANS AFFECT THE CAFFEINE CONTENT OF THE COFFEE?

As we indicated in the introduction, people have a lot of questions about the caffeine content and roasting of beans. They often think that dark roast coffee contains more caffeine because it has a strong flavour .

If we try to put this statement into perspective, the caffeine content of the beans does not change, it may only vary in the amount of beans roasted to grind and prepare the beverage. If we weighing a batch of beans intended, for example, for a cappuccino (i.e. about 8 g of ground coffee), by weight there will be far more dark roast beans than light roast beans. Dark roast beans are significantly lighter, evaporating water, which contributes most to the weight loss. And the coffee will actually be a little richer in terms of caffeine because it simply contains more beans. The pile of lighter roast beans will be smaller, but the caffeine content will more or less stay the same.

Again, some people are under the impression that the reason we find more caffeine in lighter roast coffee is because the coffee has been roasted at a lower temperature and the caffeine has not been affected by the high temperature (we explained how the temperature is above).

Thesame mistaken impression that light roast coffee contains more caffeine can arise when the dose of light roast beans is determined by the size of the beans "by eye", for example when making home coffee. The pile will be bulkier with alarger number of beans. It's only a step from that to thinking thatif there are more beans, they contain more caffeine. That is, each bean in a measured dose contains more caffeine and lightly roasted beans contain more caffeine in general.

However, the caffeine content could increase radically if you used Robusta instead of Arabica, or a blend where Robusta predominates.

DOES ROBUSTA OR ARABICA CONTAIN MORE CAFFEINE?

Perhaps this coffee myth also stems from the low awareness of customers who buy Robusta one time and Arabica the next. There is a big difference in the caffeine content of these coffee varieties. Robusta contains up to three times more caffeine than Arabica.

Robusta has a more earthy taste and is more bitter than Arabica. The coffee plant is not as demanding to grow as Arabica, it produces in 2 to 3 years after planting and does not need as many herbicides. The biggest producers of Robusta are Vietnam, Brazil and India.

THE UNTANGLED END

It's convoluted, but it's by simplifying some of the problems that modern urban legends like this are created. So, to untangle it definitively:

Actually, you could say that almost everything in the coffee bean changes during roasting, except the caffeine content. The weight and size of the beans, the colour and, most importantly, the flavour nuances of the beans and their aroma change.

Thecaffeine content is most influenced by your choice of coffee and the way it is prepared.