How is decaf coffee made?
Caffeine-free coffee has come a long way since its early days. The process of removing the magic molecule from beans was invented by German merchant Ludwig Roselius who commercialized the product under the still successful ‘cafe HAG’ brand. Early attempts at removing caffeine relied on treating the beans with solvents such as benzene. This damaged the beans and affected the quality of the coffee, making it harder to roast accurately.
Chemical solvents including ethyl acetate or methylene chloride are still used today, but a new breed of demanding coffee customer has helped drive the push towards chemical-free methods of production. Today’s more natural methods are gentler and do a much better job of preserving the flavour of coffee beans. The two most popular ‘natural’ ways of doing it are called the ‘Swiss Water Process’ and the ‘C02 Process’ (both are explained below). When choosing a decaf, look for these as chemical methods affect compounds key for the flavours and aromas of the magic bean to a much greater degree.
The Swiss Water Process
This involves soaking raw beans in caffeine-free green coffee extract as a solvent. As the beans steep, their caffeine is drawn out into the liquid. The coffee is drained out and the beans are dried and bagged.
While a natural and gentle process, the same solvent is often used to treat a vast number of batches of beans, which some say flattens out the unique flavour and aromas of any individual bean.
The C02 or ‘sparkling water’ process
This involves soaking raw beans in water and in a sealed tank and pumping C02 into the beans at very high pressures. This draws out the caffeine but leaves larger molecules responsible for taste behind.
Neither method is perfect. Chemical and flavour profiles of beans are almost always affected in some way by the treatment process. However, the industry is light years ahead of where it was 30 years ago and it is possible to get some very delicious decaf coffees that are worth every penny.