Decaf – how is coffee decaffeinated?

While coffee as a typical stimulant forms part of our daily routine in the morning, tea or the decaffeinated variety is often the preferred beverage in the evening. There are, however, many reasons for drinking coffee with or without caffeine. Most commonly it isn’t a matter of taste, but rather a choice based on health reasons. Decaf can taste really rich and doesn’t need to be considered a second-rate alternative – as proven by our "LEGAL" coffee. We gladly show how our coffee is decaffeinated and what other methods exist.

Each of the variants passes through the same three initial steps. Nonetheless they vary in expenditure of time, cost and tasting notes.

  1. Moisturising the beans
    By exposing the beans to hot steam, pressure or warm water they are allowed to soak, thus preparing them for the second step.
     
  2. Decaffeination using solvents
    The solvent binds with the caffeine in the beans, thereby separating it. This extraction process should be repeated several times, in order to remove as much caffeine as possible.
     
  3. Drying the beans

The beans must be dried before they can be further processed.

VARIANTS

Ethyl acetate

Following the steam or water bath treatment of the coffee beans, they are placed in an extraction vessel filled with ethyl acetate for several hours. Ethyl acetate is derived from natural sources. It is already contained in coffee beans and can be found in other fruit and vegetable varieties as well as in sugar cane. This bath will be repeated several times to extract a large part of the caffeine. The beans are then being treated with steam and pressure, thereby removing the remaining caffeine. Owing to the nature of this procedure, these decaf beans are also being referred to as naturally decaffeinated coffee. Our "LEGAL" coffee beans are being decaffeinated by the enterprise Descafecol from Manizales/Colombia by adopting this gentle procedure with ethyl acetate from sugar cane. The extracted caffeine is being sold to Coca Cola and other companies, while the ethyl acetate is being composted.

Supercritical CO2

Firstly, the coffee beans are being prepared with steam. Supercritical CO2 is then washed over the beans with a pressure of between 73 and 300 bar. Supercritical CO2 is formed when carbon dioxide is in a fluid state above its critical temperature and above its critical pressure. As a result, the caffeine is dissolved in the so-called fluid phase. The carbon dioxide evaporates and is collected, compressed, condensed and subsequently reused. What remains is pure caffeine. Due to its highly efficient process that doesn’t utilise added solvents, this method is used for decaffeinating organic coffee beans.

Swiss Water Process

The method behind “Swiss Water Process”, that was developed at the end of the 1970s, relies on a larger number of work steps than the variants that don’t use added solvents. In this process, the coffee beans are first placed in hot water until the caffeine, as well as other solid components of the beans, are dissolved out. The water is then separated and the depleted coffee beans discarded. In the second step, the water containing the coffee components is filtered with activated carbon to allow for the removal of the caffeine. What remains is the water containing the other solid components of the beans, which is now heated and added to a fresh batch of beans. Since the liquid is already enriched with the solid components of the beans, only the caffeine is extracted from the new beans while the natural coffee components remain. This process can be repeated until the desired degree of decaffeination is achieved. Despite the high costs of this method, it is widely used, as it manages to preserve the taste of the coffee in a natural way.

Methylene chloride

The variant of decaffeinating with methylene chloride is a chemical method. The beans are placed in a basin filled with the solvent for several hours. Diffusion causes the caffeine first to be carried to the surface of the beans where it is then absorbed by the organic-chemical compound. Lastly, the beans are completely dried in order to remove any residuals.

Overview of the methods

 

 

Differentiating feature

Expenditure of Time

Taste

Effort vs Cost

Methods

 

Ethyl acetate

Medium expenditure due to several rounds of water baths

Mildly acidic, balanced out through roasting

Inexpensive despite expenditure of time, thanks to high efficiency

Supercritical CO2

Medium expenditure, as three types of CO2 are being applied (liquid, solid, gaseous)

Acidic, slightly sweetish

Moderate, CO2 is collected and reused

Swiss Water Process

Longest process

Mildly acidic, yet almost neutral as processed with water

High effort and high cost

Methylene chloride

Fast process

Acidic, tasting notes of vegetables since chemicals are involved

Least expensive method as fast and efficient

 

Descafecol, Manizales/Colombia, offices
Descafecol, Manizales/Colombia, keeping things under control
Descafecol, Manizales/Colombia, tanks with coffee beans
Descafecol, Manizales/Colombia, 100% Caffeine
Descafecol, Manizales/Colombia