Decaffeinated Coffee – Fact and Fiction


I’ll aim to keep this blog fairly short and sweet as it’s very easy to get caught up in the long grass when it comes to the different decaffeinating processes and the impact it has on your cup of Joe. There are plenty of websites out there who will go into the chemistry but few talk about what really matters and that is the taste.

There are 3 decaffeinating processes:

1. MC process or European preparation;

2. CO2 process;

3. Swiss Water Process.

All are challenging to roast as it is clear that something happens to the cell structure of the coffee during the removal of the caffeine which slightly impairs its original flavour.

1. I’ll start with the MC or methylene chloride (CH2Cl2) process or dichloromethane (in Europe).  MC is a solvent and before I go any further its use as a decaffeination agent is not considered a health risk.

Although the word “chemical” can sound scary, the colourless liquid is highly volatile and vaporises at 40 degrees C. If you take into consideration that coffee is roasted at a minimum of 190 degrees C for at least 10 minutes, and that proper brewing temperature lies between 88-92 degrees C, it seems unlikely that much, if any, methylene chloride would end up in your coffee cup. The taste though is a very different matter. Personally I find this method is the least forgiving when it comes to the resultant taste. The final coffee lacks character and compares with alcohol-free wine or beer. It appears that it isn’t just the caffeine that is lost. 

2. CO2 process

The Carbon Dioxide (CO2) method is the most recent innovation. Liquid CO2 is used in place of chemical solvents. It acts selectively on the caffeine. Because of its cost, this process is primarily used to decaffeinate large quantities of commercial-grade coffees rather than the finer specialty grades. Lower quality in must inevitably mean lower quality out.

3. Swiss Water Process (SWP)

The Swiss Water Process uses Green Coffee Extract (GCE) for the caffeine extraction mechanism. Green Coffee Extract is a solution containing the water-soluble components of green coffee except the caffeine. The process relies on the stability of the soluble components of the GCE and the gradient pressure difference between the GCE (which is caffeine lean) and the green coffee (which is caffeine rich). This gradient pressure causes the caffeine molecules to migrate from the green coffee into the GCE. Because GCE is saturated with the other water-soluble components of green coffee only the caffeine molecule migrates to the GCE; the other water-soluble coffee elements are retained in the Green Coffee.

Although the Swiss Water Process seems to be the least “invasive” process for removing caffeine it is still a challenge to roast. It does however retain most of the individuality of the original coffee and therefore it gets my vote as the best decaffeinating process currently available.

You can purchase Swiss Water Process decaffeinated coffee from Cooper & Co by clicking here.

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