How Is Caffeine Removed From Coffee?

How is caffeine removed from coffee is a common query of many people, as this is a challenging proposition considering coffee contains caffeine, which is just one of the 400 different chemicals and compounds that lends this drink its distinctive flavor. However, too much caffeine is not considered healthy in the long run according to medical research and so many manufacturers use different methods to decaffeinate coffee beans before roasting them.

This means, it is the raw or green coffee bean that actually undergoes the caffeine removal process. This is called decaffeinating.

Ludwig Roselius was the first person to remove caffeine from coffee and that was over 100 years ago. He was a German coffee trader and when one of his shipments of coffee got soaked in transporting it by sea, he set upon the idea of ridding it of the salt-water in it to salvage the merchandise. That was in 1905. During his experimentations for salvaging the coffee shipment, he discovered through trial and error that the brine-soaked coffee could be treated with a benzene solvent. By doing this, the caffeine bonded with the solvent (benzene).

The scientific fact behind the above method for removing caffeine from coffee lay in caffeine being a water-soluble element if its temperature was raised more than 175°, which Roselius did for separating the caffeine content from his coffee shipment. However, he realized that in doing so, his coffee had lost much of its flavor, so he improved on this process and then sold his discovery pretty successfully under the brand name, Sanka.

Further research proved that edible products treated by Benzene were unsafe for human consumption identifying it as a carcinogenic substance and thereafter this method was discarded. 

One can even come across edible products and beverages with the tag ‘uncaffeinated’ on them, which only means that caffeine has been omitted in their preparation.

For those wondering how is caffeine removed from coffee, here are some of the most widely accepted methods of decaffeinating coffee, with some variations to all of these used across the world:

• Swiss water process

this method was popularized during the 1930’s by Swiss scientists and required coffee beans to be soaked in hot water, which was one way of extracting the compounds in it (the soluble as well as the semi soluble elements besides the caffeine). The beans are disposed off after all the coffee solids and the caffeine has been seeped into the water. Thereafter this water containing caffeine in it is put through a carbon filter that functions as a caffeine molecule capturing unit and fresh beans are soaked in this flavor-enriched water; this step is repeated until all the caffeine is filter out. The expense and labor involved in this method has made it pretty much redundant in modern times.

• Indirect method

It is similar to the first step of the Swiss water treatment process for decaffeinating as beans are put under hot water for a couple of hours. Then, ethyl acetate is added to the water (even methylene chloride may be used for the same purpose) so it makes the extraction of caffeine possible. A fresh batch of coffee beans is thereafter soaked in this water; process is repeated till the desired results are obtained – that is, beans as well as the water have same taste and fragrance but minus the caffeine.

• Direct method

This process requires the coffee beans to be steamed and washed out completely after that using methylene chloride or ethyl acetate for 8-10 hours before they can be rinsed out again and finally steamed once more for eliminating any solvent in them.