While many people drink coffee for the energising effects of caffeine; often there is the need for the delicious flavour of coffee without it keeping you wide awake. Decaf coffee is often ignored or even hated by coffee lovers; but this could be because some decaffeination processes not only remove the caffeine- but also much of the flavour. So we’ve compiled three methods that remove the caffeine but not the flavour; meaning if you buy decaf that’s used these methods- we reckon it’ll still be a delicious cup of joe! (This post has a little bit of science going on- feel free to leave any questions in the comments)
The first time coffee was decaffeinated commercially was in a process invented by a guy called Ludwig Roselius in 1903, who used a chemical called benzene to remove the caffeine from the coffee bean. However, benzene is now thought to cause cancer, so this method is no longer used. Common modern methods include the Ethyl Acetate method, the CO2 method and the Swiss Water Process.
The Ethyl Acetate method is based on the caffeine dissolving into a solvent. The Ethyl Acetate is the solvent in this method. Ethyl Acetate naturally occurs in nature in certain fruits and plants; so is often naturally sourced by fermenting sugar cane.
Ethyl Acetate can be found in Sugar Cane.
Coffee is always decaffeinated in its green- unroasted state, so the ethyl acetate process begins with the green beans being steamed to open up the pores in the bean. They are then repeatedly rinsed in Ethyl Acetate for about 10 hours, in this time the caffeine in the coffee bean dissolves into the ethyl acetate. The solution of dissolved caffeine is drained away and the beans are steamed once more to ensure there is no residual caffeine or solvent in the bean.
The CO2 process is another method used, CO2- or Carbon Dioxide, can selectively bind with caffeine- meaning it is ideal to remove the caffeine from the bean. The process starts with the green coffee beans being soaked in water to open the pores. These beans are then placed in an extraction chamber where carbon dioxide in its supercritical form (it is in between being a liquid and a gas) is forced into the extractor at high pressure. Any caffeine in the beans will then bind to the carbon dioxide and be removed from the chamber. The Carbon Dioxide can then be separated from the caffeine and be re-used.
Another process used is the Swiss Water Process. This process occurs because of diffusion- caffeine will move from areas of high concentration to areas of low concentration. Therefore the process must create an area where there is low caffeine concentration, for the caffeine from the coffee beans to move into.
It usually starts with a batch of coffee beans being soaked in hot water which removes all of the caffeine, plus all of the oil and flavour molecules. The beans are discarded, leaving water which is rich in both caffeine and flavour. The water is then passed through an activated charcoal filter, this acts like a sieve, letting all the small flavour molecules through- but not the larger caffeine molecules. This leaves water which is caffeine free- but rich in flavour molecules. Fresh coffee beans are then placed in this solution- because there is more caffeine in the bean than the solution, the caffeine will leave the bean and dissolve into the solution. However, because the solution is rich with flavour molecules- and so are the coffee beans, none of the flavour is removed from the coffee- just the caffeine.
As you can tell- the decaffeination can be a long and scientific process- which coffee loving researchers have spent time on to get really tasty coffee to you minus the caffeine! Here at The Cambridge Coffee Company we love some decaf coffee.
Our Light Blue Coffee is decaffeinated using the ethyl acetate method- using naturally sourced ethyl acetate from fermented sugar cane. This makes it a natural process which leaves the coffee full of flavour since the ethyl acetate only affects the caffeine in the bean. It’s a delicious decaf, so much so its difficult to notice any lack of caffeine. So try some Light Blue Coffee here and see if we can convert you!