Decaf, a method to remove caffeine from coffee

Decaf, or coffee with the caffeine removed, comes into play when you need to reduce your caffeine intake for a variety of reasons.

In this article, we will explain some ways to remove caffeine.

What exactly is decaf?

Decaf refers to coffee that contains only a small amount of caffeine.

In Japan, coffee can be labeled as ``decaffeinated coffee'' or ``decaffeinated coffee'' if 90% or more of the caffeine has been removed, but in Europe, coffee beans with a caffeine content of 0.2% or less can be labeled. Without it, you can't call it decaf.

Some coffees are naturally low in caffeine, and some coffees have been genetically modified to be caffeine-free.

However, the commonly encountered decaffeinated coffee has undergone a chemical process of decaffeination.

There are several ways to remove caffeine from coffee, which is done in the green state before roasting. By roasting it, decaf coffee is made.

Decaffeinated coffee generally tastes a little different than caffeinated coffee. Its variations depend on the original coffee and the method used. All methods also usually leave behind a small amount of caffeine.

Four typical ways to remove caffeine

Here are some steps to get rid of caffeine.

methylene chloride process

Methylene chloride is also called MC or dichloromethane. It's a chemical solvent process where green beans are soaked in hot water and methylene chloride is added to draw out the caffeine.

It then filters out the MC/caffeine binding particles and rehydrates the beans. However, there are concerns about carcinogenicity, and the use of MC/dichloromethane as a solvent is prohibited in Japan.

Ethyl acetate/sugar cane process

Ethyl acetate (EA), the solvent used, occurs naturally in rotting fruits such as bananas and blackberries, and is also a byproduct of sugar cane production.
However, EA can also be chemically synthesized from petroleum derivatives.

The process involves steaming the green beans at low pressure and then soaking them in EA to bind and draw out the caffeine particles. This method is often used to remove caffeine in coffee producing areas.

swiss water process

A unique process in which green beans are slowly soaked in water to create an extract that replaces caffeine particles. Use water saturated with ingredients other than caffeine. The coffee is filtered through a carbon filter that traps only the caffeine and allows other soluble solids and flavor compounds to remain intact.

Because no chemical solvents are added to the coffee, Swiss Water is believed to have little residual flavor from the decaf process.

mountain water process

This is a water process similar to Swiss Water, but with methylene chloride. Made by Mexican companies, Mexican decaf often uses a mountain water process.

CO2 process

This is also a process that does not involve the addition of chemical solvents and is a popular method in Europe. In this process, liquid (or supercritical) carbon dioxide pulls caffeine particles from the green beans into the liquid. The liquid is then filtered back to its gaseous state and the caffeine is separated again.

In the CO2 process, the flavor compounds remain in the coffee beans throughout the process, and the flavor properties are said to be well preserved.

So far, we have introduced the most commonly used caffeine removal methods.

There are differences in the presence or absence of chemical solvents and the effect on flavor, so when handling or drinking decaf coffee beans, it is said that you should check the method used to remove caffeine. Please use this as a reference when choosing a decaf.