How is coffee decaffeinated? Explained in this article
Coffee is one of the most consumed beverages in the world, appreciated for its unique aromas and flavors… but also for its caffeine. Some consumers, sensitive to the stimulating effects of this molecule, turn to decaffeinated coffee. But how is coffee really decaffeinated?
At Shoukâ, an altitude roaster in Chamonix, we care as much about taste as about the methods used. Here is a complete guide to understanding the process, its different techniques, and its impact on flavors.
What is decaffeinated coffee?
Decaffeinated coffee is coffee from which most of the caffeine has been removed, while preserving the aromas as much as possible.
-
Residual content: according to European regulations, decaffeinated coffee must contain less than 0.1% caffeine for roasted coffee, and less than 0.3% for instant coffee.
- Objective: to allow you to enjoy the taste of coffee without the stimulating effects or sleep disorders associated with caffeine.
When and why decaffeinate coffee?
Decaffeination takes place before roasting, directly on the green (unroasted) beans.
The main reasons:
- To offer an alternative to people sensitive to caffeine.
- To allow consumption in the evening without disrupting sleep.
- To meet certain medical recommendations.
The main decaffeination methods
There are several processes, some of which are more natural and respectful of aromas than others.
1) The water method (Swiss Water Process)
Principle: the green beans are immersed in hot water to dissolve the caffeine.
The water is then filtered through an activated carbon filter that retains the caffeine, but allows oils and aromatic compounds to pass through.
The beans are then re-infused with this "aroma-saturated" water to preserve their flavor profile.
Advantages: 100% free of chemical solvents, a method considered natural.
Origin: developed in Canada, widely used for specialty coffees.
2) The carbon dioxide method (supercritical CO₂)
Principle: the green beans are placed in a high-pressure tank, then exposed to supercritical CO₂ (between liquid and gas).
The CO₂ specifically targets the caffeine and extract without altering the other aromatic compounds.
Advantages: clean process, reuse of CO₂, excellent for preserving aromas.
Use: often adopted by industrial manufacturers for large volumes.
3) The solvent method (chemical method)
Two types:
-
Direct: the beans are exposed to a solvent (generally ethyl acetate or methylene chloride) after being moistened.
-
Indirect: the beans soak in water, then the water is treated with the solvent to remove the caffeine before being reinjected.
Advantages: fast and efficient process.
Disadvantages: negative perception among some consumers, although the solvents used are authorized and removed during the process.
4) The natural sugarcane method (natural ethyl acetate)
Principle: ethyl acetate is of natural origin here, obtained from the fermentation of molasses from sugarcane.
This acetate is then used to extract the caffeine from the beans after they have been exposed to steam to open their pores.
The beans are immersed in a solution of water and ethyl acetate for several hours. The ethyl acetate binds to the caffeine and allows its extraction, while preserving the aromas of the coffee.
After extraction, the beans are carefully rinsed, dried, then prepared for export.
Advantages:
- Process 100% natural, without synthetic solvents.
- Preserves aromas well.
- Ideal for lovers of smooth and complex coffees.
Use: this method is the one we use at Shoukâ for our decaffeinated coffees, in a logic of respecting the product, the taste, and the naturalness of the process.
The impact on the taste of coffee
The challenge of decaffeination is to preserve the aromatic profile as much as possible.
- The water, CO₂, and sugarcane methods generally give the best results in terms of taste.
- Chemical solvent processes can slightly alter the aromatic profile, although recent technologies reduce this impact.
At Shoukâ, we favor natural processes, without synthetic solvents, to guarantee a rich, complex, and balanced coffee.
Myth or reality: is decaffeinated coffee really caffeine-free?
No, no process eliminates 100% of the caffeine.
A decaffeinated espresso can still contain between 1 and 7 mg of caffeine, compared to 60 to 80 mg for a classic espresso.
This is enough for some very sensitive people to feel the effects.
In summary: the different methods for decaffeinating coffee
Method |
Natural? |
Preservation of aromas |
Common use |
Water (Swiss Water) |
Yes |
Excellent |
Specialty coffees |
Supercritical CO₂ |
Yes |
Very good |
Mid-range production |
Chemical solvents |
No |
Good to average |
Classic industrial production |
Sugarcane (natural acetate) |
Yes |
Excellent |
Specialty coffees (e.g., Shoukâ) |
Sources
