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A Crash Course in Decaf Coffee
Everything you need to know about decaffeinated coffee
Published July 16, 2021
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Asharita D'Silva
Coffee experts@Era of We
For the millions of people that drink coffee every morning, the main thing they’re looking for is that caffeine kick. Caffeine is the active ingredient in coffee and is responsible for its energizing effects. Caffeine can be great but what if you want decaf coffee, the type without the effects of caffeine? For people trying to cut caffeine for personal or medical reasons, or those who are sensitive to caffeine, there’s always decaf coffee.
Love it or hate it, decaf coffee is a staple for many people and a great way to enjoy coffee without the side effects of caffeine.
What Is Decaf Coffee?
Decaf is short for decaffeinated. Therefore, decaf coffee is coffee without caffeine. This process removes almost all the caffeine in coffee. However, one can apply the process to other caffeine-containing products like tea and cacao. Still, it’s not a perfect process and trace amounts of caffeine are around. There is not enough to truly affect someone though. Black tea would likely have more caffeine than decaf coffee.
Decaffeination must happen before the coffee beans go through roasting, and there are many methods to do this.
Friedlieb Ferdinand Runge, a German chemist, first isolated pure caffeine from coffee in 1820. This was mostly a scientific experiment and had no commercial purpose. Later on, the science expanded to create commercial decaf coffee almost a century later in 1905. A German coffee merchant, Ludwig Roselius, successfully decaffeinated coffee for commercial use while keeping the taste of the coffee itself.
The legend goes that Ludwig Roselius received a bag of coffee that had been soaked in seawater. Instead of tossing the beans in the trash, he decided to experiment a bit and process the coffee. He found that the seawater removed the caffeine from the beans, but it still tasted like good coffee. If anything, it was a bit salty. Surprised, he tested further and found a way to isolate caffeine from coffee beans using benzene, a chemical solvent. His company Kaffee HAG began selling this decaf coffee in Europe and eventually North America, where it became a staple.
These days, benzene is no longer popular, and safer methods of decaffeination have grown.
How Do You Make Decaf Coffee?
Many have created methods of decaffeination over the decades, and each comes with its pros and cons. No matter the method, decaffeination always happens before roasting, while the beans are still green. Green coffee beans can be treated with water, carbon dioxide, or organic solvents to remove the caffeine while leaving the flavour.
While each method differs, the main goal is to move the water or solvent around the coffee beans to draw out the caffeine.
Direct decaffeination
Direct decaffeination is the original decaf coffee method. The only difference is that that benzene is no longer used due to health concerns. However, organic solvents like ethyl acetate and dichloromethane are common. To do this, manufacturers first steam the green coffee bean, then rinse them with the organic solvent. This is to remove and wash away the caffeine compounds. They must repeat this multiple times till you get the desired amount of decaffeination.
Indirect decaffeination
In this decaf coffee method, instead of directly rinsing fresh green coffee beans with a solvent, manufacturers steep them in hot water. This makes a very strong brew. Then, they remove the beans and treat the water with an organic solvent to remove the caffeine in it. They then repeat this process for at least another 2 cycles.
Eventually, there is a balance between the water and the beans. The only difference in composition is the caffeine. At this point, only caffeine is getting removed while leaving the coffee flavouring compounds intact.
This process is also called ‘water-processing’ due to the key role of water in decaffeination.
Swiss Water method
The Swiss developed the Swiss water method in 1933. They commercialized it in 1980, and finally introduced it on a large scale in 1988. This method relies on water alone, without the use of organic solvents for decaffeination.
A key component of the Swiss water method is a green coffee extract (GCE). GCE is made by soaking green coffee in hot water. Then it goes through a charcoal filter to remove the caffeine. The extract is caffeine-free but it has all the other water-soluble parts of coffee.
Fresh green coffee is then added to the GCE. This creates a gradient where the GCE is caffeine-deficient and the fresh beans are caffeine-dense. This moves the caffeine molecules out of the beans and into the GCE. The GCE is then filtered again through activated charcoal to remove the caffeine. The whole process is then repeated for 8-10 hours.
Supercritical carbon dioxide
When carbon is heated and pressurised beyond its critical point, it turns into a substance that is halfway between a gas and a liquid. In this state, carbon dioxide can isolate or extract one component from another such as removing caffeine from coffee.
As a decaf coffee method, this involves steaming green coffee beans and then putting them in a high-pressure vessel containing supercritical carbon dioxide. The CO2 absorbs the caffeine molecules while the flavouring compounds remain insoluble. This CO2 then transfers into another vessel. The caffeine is washed out with water, and the CO2 gets recirculated for further use.
What Are The Health Benefits of Decaf Coffee?
Most people who switch to decaf coffee do it for health reasons. However, most studies focus on the health benefits of all coffee without differentiating between the standard and decaf variants. This makes it hard to determine which health benefits studies give to decaf alone. Broadly, these are the following health benefits:
- Reduced risk of type 2 diabetes
- Some studies report a protective effect of decaf coffee on liver health
- A slight reduction in the risk for premature death
- Protection against age-related neurological degeneration
- Decaf coffee doesn’t cause as much acid reflux as normal coffee
Is There Any Naturally Decaf Coffee?
Over the last few decades, there has been increasing interest in the possibility of growing naturally decaffeinated coffee.
A lot of research has occurred in Brazil and the term ‘decaffito’ refers to this potential naturally decaf coffee. Coffea charrieriana is a naturally caffeine-free coffee plant that scientists discovered in Kenya in 2004. This has encouraged further research into possible hybridisation. This is merging the existing coffee plant strains with new ones to produce a commercial and natural decaf coffee.
Decaf coffee is a great option for people who want milder coffee, to avoid the effects of caffeine (anxiety, heart palpitations, etc.), and those who simply want to try something different once in a while.
About the author
Asharita D'Silva
Join me in discovering the wonderful world of coffee! As a writer, coffee is my fuel and newfound passion. I love writing about new coffees, sustainability, and coffee culture around the world. I'm always discovering new things about coffee and the industry, which I share with the great community here at Era Of We.
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