Decaffeinating coffee – this is how it works

Decaffeinated coffee

Decaffeinated coffee is the ideal alternative for anyone who cannot tolerate caffeine or consciously chooses to avoid it. This way, no one has to miss out on the enjoyment of aromatic coffee – completely without its stimulating effects.

Decaffeination

Coffee is valued not only for its invigorating effect, but above all for its intense aroma. However, sometimes you simply want to enjoy the taste – without caffeine. For people with caffeine intolerance, pregnant women, or anyone who enjoys a cup of coffee before bed, decaffeinated coffee is the perfect choice.

The inventor of decaffeination

In 1903, the German coffee merchant Ludwig Roselius, founder of the still-existing company Kaffee Hag, developed the first large-scale decaffeination process for coffee. Roselius suspected that his father—a passionate coffee drinker—had died of caffeine poisoning. For this reason, he dedicated himself to producing decaffeinated coffee.

For his process, he first soaked raw coffee beans in salt water and then removed the caffeine using benzene. The resulting coffee was largely caffeine-free, but due to the harmful benzene, it was probably more dangerous than conventional coffee. Nevertheless, the product was sold throughout Europe as "caffeine-free coffee" and was a great success.

Although modern decaffeination methods are partly based on similar principles, benzene is of course no longer used.

Swiss Water Process

That Ludwig Roselius was on the right track with his early experiments on decaffeinating coffee became clear in 1970 when a Swiss company developed a new process that does without benzene entirely.

In this so-called Swiss water method, unroasted coffee beans are first soaked in hot water until all water-soluble components – including caffeine – have dissolved into the water. The water is then passed through an activated carbon filter, which retains the caffeine. The now caffeine-free water, still saturated with flavor compounds, is poured over a new batch of raw beans and heated again.

Through the effect of osmosis, the caffeine migrates from the beans into the water, which is already saturated with flavor compounds, without any loss of other flavors. After several cycles, this results in a virtually caffeine-free coffee with a particularly pure aroma.

Although the process is rarely used today due to its high energy and water consumption, many coffee lovers appreciate the result for its pure taste. Some roasters therefore continue to rely on this traditional method – including... Mocambo, Filicori Zecchini, Essse Caffè, Cafe New York, Martella and Golden Brasil.

Chemical process

The benzene process developed by Ludwig Roselius laid the foundation for the chemical decaffeination of coffee beans. Then as now, the raw beans are treated in a chemical bath. The solvents used extract a large portion of the caffeine from the beans through direct contact. The beans are then thoroughly washed and dried.

Today, the extraction agents dichloromethane and ethyl acetate are primarily used instead of the harmful benzene.Since dichloromethane is now also suspected of being carcinogenic, ethyl acetate is increasingly being used – a compound that also occurs naturally in many fruits and plants. This process is therefore considered the most "natural" form of chemical decaffeination.

Discover all decaffeinated coffee produced using a chemical solvent process.

Carbon dioxide process

CO₂ – chemically carbon dioxide – is a colorless, odorless, non-toxic and non-flammable gas that, along with nitrogen, oxygen and noble gases, is a natural component of air.

In the carbon dioxide process, coffee beans, previously softened with hot water, are treated with carbon dioxide under high pressure. The CO₂ penetrates the beans and binds the caffeine in a targeted manner, without dissolving the flavor compounds. The caffeine is then recovered from the gas stream – a byproduct that is used for various purposes, including medical applications (e.g., caffeine tablets).

A major advantage of this process is that it does not require chemical solvents. It is therefore considered particularly environmentally friendly and gentle on the aroma.

The roasters that use the CO₂ process include: Kimbo, Lavazza, GEPA, Mrs. Rose, Mokaflor and Alps Coffee.

"Decaffeinated" is relative.

None of the methods used today can guarantee a caffeine content of 0%. Therefore, there are legal limits below which coffee can be considered "decaffeinated." In Germany, this limit is 0.1% caffeine. For comparison, regular coffee beans contain between 2% and 5% caffeine, depending on the variety.

Arabica beans, which are often used for espresso, naturally contain less caffeine than Robusta beans and are therefore particularly suitable for the production of decaffeinated coffees.

Researchers are already working on genetically modified coffee plants that naturally grow caffeine-free. However, these are not yet approved for the German market.
So it will probably be a while before we can truly enjoy naturally caffeine-free coffee.