How is Decaffeinated Coffee Made?

Caffeine is a naturally occurring chemical present in plants such as coffee plants, where it serves as a defence mechanism to repel insects. The caffeine in coffee plants is what gives coffee beans their stimulating properties but not their flavour.

High-quality Arabica coffee beans are typically 1% caffeine by weight, whereas Robusta beans have twice that amount.  At Volcano, we use Arabica beans in our decaf coffee.

In order to create decaffeinated coffee, an extra processing step has to be added to the coffee’s journey to extract the caffeine from the beans. There are multiple ways this can be done – by using chemical solvents or more natural compounds.

There are 4 main methods of producing decaffeinated coffee; the Methylene Chloride, CO2, Swiss Water and Sugarcane (Ethyl Acetate) method– the last three methods do not use chemical solvents.

At Volcano, we use the natural, chemical-free sugarcane process so let’s take a look at that method first;

The Sugarcane Process

Also known as the natural decaffeination method, the sugarcane process utilizes ethyl acetate, a naturally occurring compound found in fruits and sugar cane. Green coffee beans are steamed to open their pores and then washed with an ethyl acetate solution, which binds to the caffeine molecules and extracts them. Afterwards, the beans are thoroughly rinsed and dried.

This method is particularly popular in coffee-growing regions like Colombia, where sugar cane is abundant. Because ethyl acetate is derived from natural sources, the sugarcane method is an eco-friendly and flavour-friendly approach to decaffeination, preserving the full flavour of the coffee.

At Volcano, flavour and sustainability are at the heart of what we do which is why this was the first choice for our decaf coffee.

A note from our speciality coffee roaster, Claire:

“The caffeine in our decaf coffee is removed using the sugarcane process. This is an extremely effective, fully natural process - no chemical solvents are required.

Most importantly, this method doesn't disturb the flavour compounds in the coffee beans; meaning you don't have to compromise on taste to enjoy a caffeine-free cup!"

Try our decaf coffee beans or our decaf coffee pods.

The CO₂ Process

For the CO₂ method, the coffee beans are soaked in water and then liquid CO₂ is forced through them in a highly pressurised container so that it can dissolve the caffeine. The caffeine soaked CO₂ is then moved to another chamber where it is depressurised and allowed to turn into a gas again, leaving the caffeine behind. The CO₂ is then captured and recycled or reused again.

CO₂ is efficient at extracting caffeine but leaves the flavour components alone, so it does not affect the quality or taste of the coffee.

The CO₂ method is not only a more natural and efficient method but also a zero waste method. The CO₂ is cycled through the coffee over and over again within the process and the only waste in this process is solid caffeine which is used in other industries and for other purposes - so it doesn’t create any residual waste.

Swiss Water Process

First discovered in the 1930’s in Switzerland (clues in the name), the Swiss water process  became a mainstream method of decaffeination in the 1980’s. It’s a chemical-free, environmentally friendly decaffeination method that relies on water and osmosis. First, green coffee beans are soaked in hot water to dissolve their caffeine content. The resulting liquid is then passed through a carbon filter that removes caffeine while retaining the flavourful coffee compounds.

Next, a new batch of beans is introduced to this caffeine-free solution, allowing the caffeine to naturally diffuse out whilst preserving the flavours. This process is repeated until the beans are 99.9% caffeine-free. Because it does not use chemicals, the Swiss water process is preferred by those looking for a more natural decaffeinated coffee.

Methylene Chloride Process

The methylene chloride method is a popular solvent-based decaffeination technique. Green coffee beans are first steamed to open their pores. Then, they are treated with methylene chloride, a chemical solvent that selectively bonds to caffeine molecules and removes them. Afterward, the beans are thoroughly rinsed and dried before being roasted.

Although this is an effective way to remove caffeine from coffee, the drawback of this method is the amount of chemicals needed in the process and so is not favoured in speciality coffee production.

Now that you’ve learnt about all the different and innovative ways coffee can be decaffeinated, next time you reach for a decaf coffee, you can take a moment to appreciate the science behind it!