Decaffeination - Old City Coffee
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While coffee itself has been around for centuries, decaf has only existed for the last 100 years. Three techniques are used to decaffeinate coffee, methylene chloride, Swiss Water and carbon dioxide. During any of the decaffeinating processes, the molecular composition of the bean is altered, thus resulting in a darker bean. While, all three methods are FDA approved, Old City Coffee only carries Swiss Water and CO2 decaf varieties.

Invented in Germany in 1906, the original methylene chloride decaffeinating process superheats the raw (green) coffee beans, then floods them with solvent benzol leaving the beans caffeine free.

The Swiss Water process was created in the 1970’s due to health concerns surrounding the original method. During this process, coffee beans are soaked for hours in water that draws off the caffeine. The caffeine-rich water is then run through a pre-treated charcoal bed to remove the caffeine. Because the charcoal has been pre-treated, the amount of coffee components that would otherwise be retained in the charcoal bed is reduced. The caffeine-free mixture is concentrated and added to the partially dried coffee beans.

The newest process uses an ingredient particularly important to our environment. Carbon dioxide makes an ideal solvent for caffeine, making it possible to decaffeinate coffee naturally without chemicals, while retaining all the valuable flavor and aroma of the coffee. Both the Swiss Water and carbon dioxide methods tend to loose some vital coffee oils, but the final result is chemical free.

Check out our website for a full assortment of decaf flavors.


Decaffeinating coffee is achieved through a variety of decaffeination processes, all of which are relatively harmless to your health, but harmful to coffee quality. Almost every process for decaffeination consists of soaking the beans in water to dissolve the caffeine, extracting the caffeine with either a solvent or activated carbon, and then re-soaking the coffee beans in the decaffeinated water to reabsorb the flavor compounds that were lost in the initial extraction. The solvents typically used are methylene chloride or ethyl acetate, which both have a low boiling point. Since ethyl acetate is found naturally in fruits you will hear people call this process “natural.” In any case the solvent never comes in contact with the coffee bean itself, but only the water solution containing the caffeine that was previously extracted from the coffee bean. Therefore the water decaffeination process is relatively benign. All methods used to decaffeinate coffee are based on equilibrium principles and solvent/solute properties. As such, neither all of the caffeine is removed from the coffee, nor are all of the flavor compounds returned or left in the coffee. The chemical composition of decaffeinated coffee (or decaf coffee) is altered, and therefore the flavor and aroma are changed.

Swiss Water Process

In the Swiss Water Process, the green coffee beans are soaked in hot water to remove the caffeine and compounds responsible for much of the flavor of the coffee flavor. The first batch of coffee beans is then discarded, while the caffeine is stripped from the solution by means of activated carbon filters. This leaves a solution saturated with flavor compounds, which is then used to soak a new batch of decaffeinated green coffee beans. The principle of water procesed decaf coffee is that the solution is saturated with all components soluble in water other than caffeine. Therefore, only the caffeine in the bean is allowed to escape whereas the rest of the compounds are in equilibrium. Unfortunately, the flavor of batches is intermixed since the chemically saturated solution is used repeatedly.

CO2 Process

In the carbon dioxide decaffeination process, green coffee beans are soaked in highly compressed CO2, which extracts the caffeine. The caffeine is then removed from the CO2 using activated carbon filters, which are then reused to extract caffeine from the coffee again.

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