How is coffee decaffeinated?
How is coffee decaffeinated?

Cheekily referred to by some grizzled baristas as a ‘why-bother’, decaf is a necessity for many coffee lovers all around the world. 

There are many reasons why you might ask for a decaf coffee. 

Sleep, health, pregnancy, other medical stuff. Maybe you’re a bit sensitive to it – in fact, scientists have identified a specific gene that makes us more sensitive to caffeine’s effects. 

This means some people are more likely than others to get the jitters after a cup of coffee, and explains why some people can have a double espresso just before bed and not be affected. 

There’s also the issue of caffeine allergy, another reason to go decaf – it’s a medical condition and results in some unpleasant and harmful effects, but thankfully, it’s extremely rare. 

If you’re wondering how coffee gets decaffeinated, there are a few different methods typically used. 

Firstly, the word decaffeinated (often shortened to decaf) refers to coffee that’s had at least 97% of its caffeine removed. That’s the legal minimum for ground coffee in the UK, but the laws for instant coffee are tighter - mandating that 99.7% of caffeine is removed to earn the right to be called decaf. 

(Achieving these numbers involves repeating the removal processes multiple times until it’s almost all gone.) It’s not possible to guarantee total caffeine removal due to the way the processes work (which we’ll get to in a moment). 

There are four methods of caffeine extraction your decaf coffee can go through.

The Swiss Water® method

The first is the Swiss Water® method. This is where green (unroasted) coffee beans are soaked in water, dissolving the caffeine within. This caffeinated water is then sent through a carbon filter, taking out the caffeine, but letting the coffee flavour compounds remain. This ‘flavoured’ water is used on another batch of beans, removing the caffeine from them, but this time, the flavour compounds don’t leave the beans as the water already has maximum flavour capacity. And then you’re left with decaffeinated beans. It won’t work 100% each time, so each batch of beans is sent through this process multiple times until the caffeine content is low enough. As this is a proprietary process, it can only be done by one company, which means it can  be prohibitively expensive.

The Supercritical C02 process

The next method is the Supercritical CO2 process (also known as the sparkling CO2 or liquid CO2 process). In this method, unroasted green beans are steamed and added to a high pressure vessel. They’re then soaked in liquid CO2 (carbon dioxide, the gas used in fizzy drinks) at a relatively high temperature. This liquid dissolves the caffeine, leaving the flavour compounds in the bean mostly intact.

The direct method

The last is the ‘direct’ method involving a simple chemical-assisted extraction. Unroasted green beans are first steamed with hot water to soften them up. They’re then rinsed with a solvent (either methylene dichloride or ethyl acetate) which removes the caffeine while leaving the flavour compounds unaffected. 


Our own decaf variety coffee, (I Can’t Get No) Caffeination, goes through this method with ethyl acetate, which is a natural byproduct of fermented sugar cane. 


There’s no need to worry about safety where these chemicals are concerned – ethyl acetate itself is not harmful to humans in small quantities, and the thorough rinsing afterwards means there’s effectively never a drop of it left on the bean. There’s strict EU and UK legislation that ensures producers stick to high standards during this process. 


And don’t worry about quality, at least where our coffee is concerned. (I Can’t Get No) Caffeination is a mix of three Colombian varietals and has a fruity, sticky toffee goodness, reminiscent of a Black Forest gateau – perfect for an evening of eating, drinking and sleeping well.  

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