Everything You Need to Know About Decaf Coffee

What is Caffeine?

First things first: what is caffeine? Naturally occurring in coffee cherries, caffeine is a brain stimulant that makes us more alert. It was isolated for the first time in 1819, from a coffee bean. For all you budding chemists, here is a visual illustration of a caffeine molecule. The amount of caffeine found in coffee varies depending on the species and variety of the coffee plant:

• Coffea Arabica contains around 1% caffeine
• Coffea Canephora, including the Robusta variety, contains between 2% and 5% caffeine

These amounts will obviously vary depending on the conditions (such as terroir or specific location, altitude and shade) in which the coffee has been grown. For example, the higher the altitude, the lower the caffeine content. This is because caffeine is a natural insecticide that tends to develop more at lower altitudes in order to protect coffee plants from pests.

How is Coffee Decaffeinated?

Decaffeination is only ever carried out on green coffee (beans that have already been subject to the initial processing phase). In other words, it is always performed prior to roasting. In the vast majority of cases, the decaffeination itself is carried out at a specialist facility. Regardless of the chosen method and/or products used, coffee that is being decaffeinated will always undergo several procedures:

Following decaffeination, the coffee should have a caffeine content of 0.1% or less. Depending on the type of decaf coffee you want to make, there are several decaffeination methods to choose from. So let’s find out all about them!

* defined as having the capacity to dissolve, dilute or extract other substances without chemically changing them. For example, water is a solvent.

Decaf Coffee with Organic Solvents

1/ Ethyl Acetate Decaffeination

Ethyl acetate is made from a mixture of fermented sugar cane and vinegar. It is naturally found in grapes or rum (to be consumed in moderation). Ethyl acetate decaffeination is a very simple process. The coffee beans are soaked in various baths containing water and the solvent, until the caffeine content is reduced to 0.1% or less. After a thorough rinsing, the coffee beans are ready to be roasted.

2/ Methylene Chloride Decaffeination  

• Direct Method: The method is the same as with ethyl acetate, but the beans are given a much more thorough rinsing at the end in order to extract any last traces of methylene chloride. For health reasons, the presence of this solvent in coffee is strictly regulated at the European level.
• Indirect Method: Unlike the direct method, the aim here is to prevent the coffee beans from coming into contact with the solvent. The beans are therefore left to infuse in water in order to dissolve both the aromatic molecules and the caffeine. The beans are then removed from the water bath and the solvent is added. The water is heated so that the caffeine and solvent evaporate. Lastly, the beans are returned to the water to re-absorb the aromatic molecules that they lost.

In most cases, if the decaffeination method is not specifically indicated on the packaging, methylene chloride will have been used. 

Decaf Coffee with Natural Decaffeination 

1/ Water Decaffeination

Not even organic solvents are used here! The beans are simply infused in successive water baths until a minimum caffeine content of 0.1% is reached. Generally, caffeine is actually added in the first baths in order to accelerate the decaffeination process. Believe it or not, the caffeine attracts the caffeine!

2/ Swiss Water Decaffeination Process

The idea of this method is to produce more flavoursome decaf coffee beans than with standard water decaffeination. The procedure is therefore a little more complex:

CO2 Decaffeination: a Modern Method

This method is by far the most expensive, as it requires a significant amount of specialist equipment. Indeed, carbon dioxide decaffeination can only be carried out in a tank that can withstand a pressure of 200 bars. Allow us to explain! The grains are placed in a CO2 tank under a pressure that is 200 times greater than the earth’s atmosphere. Under such pressure, the CO2 is transformed into a state between gas and liquid, known as “supercritical”. The beans are passed through the supercritical carbon dioxide, which extracts the caffeine from them. The decaf coffee beans are then washed and dried. Whichever method has been used to decaffeinate the coffee, the caffeine is stored and resold to pharmaceutical and cosmetic laboratories or to the food industry.

Decaffeination: Does it Affect the Taste of my Decaf Coffee?

We may as well be up-front about this: decaffeination will always have an impact on the quality of the coffee and the taste of your drink! These processes change the structure of the coffee beans and, as a result, we’re left with a less expressive coffee that may well have developed what is known as a “decaf coffee taste” or “decaf coffee marker”. Many people associate the latter with the taste of liquorice. The way that the flavour is affected will depend on the decaffeination method used:

• Ethyl acetate decaffeination: This method favours the development of fruity notes. This decaf coffee will taste sweeter and more aromatic than other decaffeinated coffees, with a less pronounced decaffeinated flavour.
• Methylene chloride decaffeination: In addition to removing the caffeine and reducing the aromatic characteristics, this method can also leave an aftertaste of solvent.
• Water decaffeination: This is one of the methods that alters the aromatic profile of the coffee most strongly. The result is a decaf coffee with little expression and a strong decaf taste.
• Swiss water process decaffeination: Although the taste of the coffee will be better preserved than with water decaffeination, there will still be a degradation of the coffee’s aromatic profile. The decaf coffee marker will be very weak.
• CO2 decaffeination: This method is used on low-quality coffees and has the least impact on the flavour of your drink. However, once extracted, the decaf coffee will be relatively light-bodied. CO2 decaffeination is increasingly being used on decaf specialty coffees, as it is suitable for smaller volumes.

8 Things You Need to Know about Caffeine

When you dig a little deeper into the world of decaf coffee, it quickly becomes clear that there are questions hiding around every corner! There is a LOT of information out there regarding decaf coffee so it’s very easy to feel lost. Don’t hesitate to do your own research and read the many articles written on the subject. That’s why we’ve put together a little selection of things you should bear in mind if you’re trying to limit your caffeine consumption:

If you’ve got this far, you should now have all the information you need to choose the decaf coffee that suits you best. However, as we’ve seen, the decaffeination process does have an impact on the aromatic profile of your drink. So if you’re looking for a coffee that truly expresses the character of its terroir, and you have no problem with caffeine, then you’re still better off sticking to a good old cup of classic coffee.