The coffee connoisseurs have for a long time turned up their nose to decaf coffee – what’s coffee without the caffeine buzz? Decaf coffee has also been known to have its taste compromised by the decaffeination process. However, the process is getting better and better and sometimes people want the taste of coffee, but have no wish to stay up all night, or getting the jittery side effect caffeine sometimes brings.
There are various ways do decaffeinate coffee, so let’s have a look at them!
The Swiss water process is, well, using water. You can easily remove caffeine from coffee beans by just soaking them in water, the problem is they also loose flavour if you do that. So as to overcome this, the Swiss method soaks the beans in water that has already been saturated with the oils and other substances that would otherwise dissolve into the water. This means a lot of beans are being used because to obtain the water they first need to soak other beans in it, remove the caffeine by filtering and then soak the beans they wish to decaffeinate. The great thing is that it’s natural.
The direct method is one that uses a chemical to remove the caffeine. It’s sometimes referred to as natural as the chemical used is either dichloromethane or ethyl acetate and those occur in nature, but as it’s too difficult to extract the large amount needed synthetic versions are used for removing the caffeine. The process looks like this: the beans are steamed for 30 minutes, then rinsed with one of the two chemicals for around ten hours and then the solvent is drained away and the beans are steamed for about ten hours to remove any solvent left on them.
The indirect method is similar to the Swiss water process in the sense that it uses saturated water. It differs in that the caffeine is removed from the water using dichloromethane or ethyl acetate.
There’s also the CO2 process where pre-steamed beans are immersed in supercritical carbon dioxide in a pressure chamber at 73 to 300 atmospheres. After about ten hours the CO2 is removed, containing the caffeine, the caffeine is filtered away by use of carbon and is then recycled for the next batch. This method is often praised as no harmful chemicals are used.
Last, but not least, there’s the triglyceride method in which green beans are soaked in hot coffee, or water to bring the caffeine to the surface. Then they are soaked in a solution of oils from used coffee grounds. Under heat this means that the triglycerides separate the caffeine from the coffee beans, whilst the flavour remains. The oils are reused once the caffeine has been removed.
Two beans have also been discovered to naturally contain very little caffeine. However, there has been a debate about one of the beans as it was discovered by a Brazilian, but the bean is from Ethiopia, so as a result the coffee isn’t on the market. Another bean was found in Cameroon in 2009, but as it takes two years to germinate seeds to plant and another four before harvest, it’s as yet to be seen if this bean will be released on the market. An issue with these beans is that companies make millions on decaffeinating coffee beans as the caffeine is then sold to soft drink companies and the beans themselves can be sold to consumers, whereas with these new beans people might vote to stop drinking coffee that has been artificially decaffeinated. So as a result it might be that corporations are holding back on the natural beans, or at least that’s what people gossip about, but who knows?