How is decaf coffee made?

Coffee beans naturally contain caffeine. Although a shot of caffeine is exactly what many people are looking for when they reach for a cup, the beans can be processed to remove most of the stimulant, creating a drink that could be enjoyed any time of the day. Decaf coffee has the same taste as regular coffee, but has the majority of its caffeine removed. Decaf coffee still contains a very small amount of caffeine, around 3% compared to regular coffee, since 100% of caffeine can’t be removed completely. There are many ways to remove caffeine from coffee beans, most of which include water, organic solvents, or carbon dioxide.

Before being roasted, the coffee beans are immersed in a flow of hot water to extract the majority of the caffeine, since caffeine is soluble in water. There are various types of coffee beans, the main two being Arabica and Robusta, both with different concentrations of caffeine. Therefore, the parameters of the decaffeination process will vary depending on the mixture of coffees that need decaffeinating. Once the caffeine has been extracted from the coffee beans in the liquid phase, the coffee beans are then dried using hot air that evaporates the water used in the previous process. Once the usual moisture of coffee beans is recovered, the result is a coffee bean with a fraction of the caffeine, 97% less to be exact, which retains the same properties of flavour and feel as regular or untreated coffee beans, but with a typical cup of decaf coffee containing 2mg of caffeine, in comparison of between 70 – 140mg in a cup of regular coffee. From this moment on, the coffee beans are ready for roasting following the same method as regular or untreated coffee, which gives rise to NESCAFÉ^® decaffeinated coffee.  

Methylene chloride is a chemical solvent that removes caffeine from coffee beans. Back in the day, benzene was the chemical of choice until it was discovered to be carcinogenic . Now, companies have switched to other chemicals, most commonly ethyl acetate and methylene chloride. However, there has been more controversy about methyl chloride, due to exposure to high amounts being toxic and leading to central nervous system damage. First, the beans are treated with steam to draw the caffeine from the inner coffee bean to the outer surface area of the bean. Once this has been done, the Methyl Chloride is applied directly to the beans, removing the caffeine, the steam is again applied to the coffee. This drives out any residual solvent. Then, the beans are dried and roasted just like any other green coffee bean. This type of decaffeination removes between 96% and 97% of caffeine from a batch of coffee.