How is Coffee Decaffeinated?

As coffee lovers become more health conscious, they are aware of their total caffeine intake throughout the day. Consuming too much caffeine can actually lead to a number of health issues, including insomnia, anxiety and digestion problems. 

With this in mind, decaf coffee is becoming increasingly popular! However, there is a stigma that decaf coffee is tasteless and therefore not as desirable as regular caffeinated coffee. But, with so many top quality brands venturing into the decaf space, there are some great tasting decaf coffees out there. 

But, you may not realise that removing the caffeine from coffee is actually quite a laborious process. There is much more to a simple serving of decaf coffee than meets the eye, so let’s find out more about how coffee is decaffeinated!

What is Decaf Coffee?

Decaf coffee is of course the same as regular coffee, but just with the caffeine removed! It is typically associated with lower quality, worst tasting coffee, as the methods used to produce it were historically dependent on chemicals. 

This tainted the reputation of decaf coffee, making coffee lovers perceive it as undesirable or low rent. 

However, as many specialty coffee makers have become more popular and accessible in recent years, the coffee industry has begun to boom. Not only do coffee roasters want to offer great tasting regular coffee, but they want to cater to the decaf market too! 

Decaf coffee has also become more popular as the general population of coffee drinking countries have become more health conscious. Much like tobacco and alcohol, the caffeine found in coffee should be consumed in regulated quantities to optimise health. Whilst the amount of caffeine found in coffee is much less harmful than smoking a cigarette or drinking a pint of beer, consuming too much caffeine can have adverse effects on your health. 

Nowadays decaf coffee hardly tastes different to regular, caffeinated coffee! 

How is Coffee Decaffeinated? 

So you may be wondering, how do you actually get the caffeine out of the coffee bean? Well, as with most things, unfortunately there isn’t an easy answer! 

Caffeine is a substance that naturally presents itself in coffee beans, so there are extra steps required to remove it. Caffeine is an adenosine receptor blocker, and stops us from feeling tired rather than actually giving us a natural energy boost. 

Caffeine molecules are removed from coffee beans by various methods that involve dissolving the substance away. There are a number of different ways to do this, some involving chemicals and some not. 

Below is an in depth look at how coffee beans are actually decaffeinated, so you know exactly what you’re drinking when you pick up that decaf cup of joe!

Swiss Water

Green coffee beans are soaked in hot, purified water, which releases their natural compounds, including caffeine. The coffee ‘soup’ is then passed through a carbon filter, which removes the large caffeine molecules but lets the flavour compounds pass through. 

The warm, softened coffee beans are then added back to the filtered coffee extract to maintain the strong coffee aromas and flavours. 

Pure, flavourful, 99% caffeine free coffee beans are left behind and are ready to be roasted! 

The Swiss Water method is generally considered the cleanest, most natural way to remove caffeine from coffee. It is preferred for the majority of high quality, organic decaf coffee bean manufacturers. 

Direct Solvent

The direct solvent decaffeination method involves submerging softened coffee beans into a chemical solution. The most commonly used substance for this process is ethyl acetate, but methylene chloride also works in a similar way. 

One of the reasons that decaffeinated coffee often gets a bad wrap is because of this chemical washing process, which some consumers have branded as unsafe. However, the facts remain that chemical decaffeination is perfectly safe, so the idea that decaf coffee is full of chemicals is unfounded. 

However, whilst the action of both ethyl acetate and methylene chloride are similar in terms of their ability to remove caffeine from coffee beans, the former is a naturally occurring ether found fermeding sugarcane, whereas the latter is a chemical found in paint strippers. 

You may think that a naturally occuring substance such as ethyl acetate would be preferable, given it is a ‘natural’ way of removing caffeine from coffee beans themselves. It works by binding to the caffeine molecules, thus removing them from the ripe coffee beans once the liquid is flushed away. 

However, in order to produce it in vast enough volumes to be used on an industrial scale, the substance has to be synthesised anyway. This actually has the knock on effect of altering the flavour profile of the green coffee beans before they are even roasted, which is not necessarily desirable for all coffee tasters. 

As such, the ‘chemical’ based solution of methylene chloride is a lot more commonly used when mass producing decaf coffee. This works by washing the beans repeatedly in order to strip away the caffeine molecules. Whilst there is some stigma attached to this, the reality is it’s the most cost effective, efficient and productive way to process decaf coffee and it simply creates a superior product. 

The green coffee beans are put into either of these chemical solutions and left to soak for 10-12 hours. They are then removed and washed to ensure they are clean for roasting. 

The coffee beans are washed in their chemical solution a number of times over in order to remove the caffeine molecules. The direct solvent method is the most widely used method of coffee decaffeination, despite it not being the most natural.

Indirect Solvent

A more complicated but arguably ‘cleaner’ method of removing caffeine is the indirect solvent method. Unroasted coffee beans are boiled vigorously to remove all of the soluble oils and substances from them. Doing this also helps open up the beans, making them more susceptible to adding the flavour compounds back to them, when they are added to the solution. 

Methyl chloride (the same chemical used in the direct solvent method) is then added to the boiling water based solution that now contains both the coffee’s flavour compounds and caffeine. Methyl chloride then binds to the caffeine and evaporates away, leaving behind a flavourful coffee soup! 

The drained coffee beans are then added back to the soup so they can reabsorb their original flavours. 

Although chemicals are used, they technically never come into contact with the coffee beans themselves, hence the name ‘indirect solvent’. 

Supercritical Carbon Dioxide 

This space age technique involves adding coffee beans to a highly pressurised vessel containing carbon dioxide. Under intense levels of pressure, carbon dioxide becomes a liquid-like state which extracts the caffeine from the coffee beans themselves. 

The coffee beans themselves are soaked in the hot water which, like with your face, helps to open up their pours. Then, these softened beans are poured into a pressurised vessel, which also contains supercritical liquid carbon dioxide. 

The container is then placed under intense pressure (around 300 atmospheres), which helps the liquid carbon dioxide extract the caffeine from the coffee beans. The natural pours of the coffee beans are just large enough to release the tiny caffeine molecules, but not so big that they let any of the larger flavour producing molecules escape. 

The liquid carbon actually passes through a filter that is built into the machine, which effectively scrubs off the unwanted caffeine molecules, leaving behind purely decaf coffee beans! 

After around 12 hours, the pressure is reduced to normal levels and the carbon dioxide solution returns to its gas state. It is filtered out of the container using, again, an activated charcoal filter. This CO2 containing the caffeine from the coffee beans simply evaporates away! 

Which Process is Best?

All of the coffee decaffeination processes above have their pros and cons. There isn’t one that is necessarily perfect, but each has their merits. 

Below is a table highlighting the key characteristics of each coffee decaffeination method: 

Summary

Overall, there are a number of different ways to remove caffeine from coffee, and not all of them involve chemicals! Despite the bad wrap that decaf coffee often gets, drinking it is not actually a health concern, nor does it have to taste any worse than regular coffee! 

Look out for the method of caffeination on your next bag of decaf coffee and see which one you prefer. 

Related Questions

Is it Healthy to Drink Decaffeinated Coffee? 

Simply, yes! Lowering your caffeine intake can have a myriad of health benefits over time, including better sleep, better digestive health and higher energy levels (yes you heard right). Becoming desensitised to the caffeine in coffee can actually cause you to need more to feel awake in the morning, and your overall energy levels will crash if you don’t fulfil these needs. 

Also, whilst some decaf coffee use chemicals to remove caffeine, there are such small doses of these that they pose no significant health risk to decaf drinkers. 

How is Coffee Naturally Decaffeinated?

The most natural form of coffee decaffeination is the Swiss Water Method. No chemicals are involved here, just water and time! 

Is Decaf Coffee Full of Chemicals?

No, not at all! Whilst some methods of coffee decaffeination do use chemicals, they are separated from the finished product so you won’t actually be consuming them when you drink a cup of decaf coffee. 

Which Coffee Beans are Naturally Low in Caffeine?

There are some coffee bean varieties that are naturally low in caffeine. Whilst Arabica beans are by far the most popular, followed by Robusta, these are quite high in caffeine. 

Whereas, the rare Racemosa Bean is naturally very low in caffeine. Whilst it is not completely caffeine free, it does contain less than a third of the caffeine of a regular Arabica coffee bean.