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Decaffeination Method - Direct Solvent Process vs Indirect Solvent Process

Why are coffee beans decaffeinated? Who came up with this idea? What procedures are there for this and are they harmful to health?

Many people are asking the above questions and for a good reason. There are a few processes for coffee decaffeination and it’s best you know what happens during these processes and how that affects your coffee.

Today, I will talk to you about two of these processes: the direct solvent process, and the indirect solvent process.

Decaffeination Method - Direct Solvent Process vs Indirect Solvent Process

How it all started

The year is 1903. Ludwig Roselius, a Bremen coffee trader and founder of the well-known coffee brand “Kaffee HAG”, produces decaffeinated coffee for the first time. The reason for this was a sad one. Shortly before that, his father dies and Roselius attributes his death to an excessive consumption of coffee and caffeine.

So he took it into his own hands and examined the effects of the delicious drink on the human body. After about three years of research, he developed a method to decaffeinate the coffee beans - the Roselius process named after him.

Whole beans were placed in salt water to swell and then the caffeine was extracted with the help of benzene. You will hardly find this method anywhere these days, because benzene is a substance that is considered to be carcinogenic.

Caffeine-free Coffee vs. Decaffeinated Coffee

The name is actually self-explanatory - decaffeinated coffee is coffee without caffeine, isn't it? “Caffeine-free” is unfortunately not the right name and often leads to misunderstandings, because the coffee is not completely caffeine-free.

The Federal Ministry for Consumer Protection, Food and Agriculture explains in the Coffee Ordinance: The word “decaffeinated” can be used for green coffee and roasted coffee that contains a maximum of one gram of caffeine in one kilogram of dry coffee.

japanese coffee


According to this, decaffeinated coffee still contains small amounts of caffeine - a cup of No Coffee has an average caffeine content of a maximum of 3 mg, whereas a normal cup of coffee has up to 140 mg!

For a long time decaffeinated coffee was accompanied by a bad reputation, today it can easily keep up with caffeinated coffee! In the course of the decades, many processes have been established which, above all, have improved the quality and taste of the coffee. The reason for this is the gentler processing of the beans, so that there is no longer any health risk for coffee lovers.

Two of these methods are the direct solvent process and the indirect solvent process.

The direct method

Here, the caffeine is extracted from the beans using chemical solvents. The coffee beans are left to swell in hot water or steam for about 30 minutes and then treated for 10 hours with various solvents such as dichloromethane and ethyl acetate.

A step that has to be repeated several times in order to achieve the maximum amount of 0.1% caffeine prescribed in the coffee regulation. Ethyl acetate is harmless. It is found in fruits and vegetables, such as cane sugar, from which it is preferably extracted for decaffeination.

With this solvent, the coffee can be described as "naturally decaffeinated". Dichloromethane, on the other hand, is considered carcinogenic and must be completely removed during decaffeination for safe consumption.

black coffee in white mug

The indirect method

The decisive advantage over the processes already mentioned: the indirect method does not require any additives, it works without any harmful chemicals. This is also the case with the Swiss water process from the 1970s, with which our beans are decaffeinated.

The aim here is to extract 99.9% of the caffeine from the coffee beans with just four elements: water, coffee, temperature and a little time. So here, too, raw beans are placed in hot water until the caffeine and solid components have dissolved. This water is filtered through an activated carbon filter, which removes the caffeine molecules.

The filtered, decaffeinated water is then heated and new beans are added. In this process, only the caffeine is extracted because the liquid has already been saturated with the taste-determining ingredients of the coffee beans in the previous step. A time-consuming and costly process.

Although both direct and indirect solvent processes are not harmful to health, unfortunately they both strip the coffee from its natural flavor and aroma. This is why many a time decaf coffee doesn't taste as good. Fortunately, there are other methods like the one we use at Japanese Coffee Co. that ensure your coffee’s taste and aroma remains intact! 

process of decaffeination


Is there no coffee plant that naturally has no caffeine?

All these procedures are well and good, but wouldn't a coffee plant that inherently contains no caffeine be the easiest solution? Around 10% of the coffee traded worldwide is decaffeinated.

And yes, decaffeinated coffee does appear to grow naturally too, but it is rarely found. Brazilian researchers discovered a naturally caffeine-free coffee plant in Ethiopia as early as 17 years ago. So far it has not been profitable enough for trading.

So an attempt is being made through genetic engineering to cross this coffee plant with other commercially used “Arabica” varieties so that it can be grown on plantations.

Who is decaffeinated coffee for?

Decaffeinated coffee is particularly suitable for those who suffer from caffeine intolerance. This is not as rare as you might think. Many people do not even know that they suffer from an allergy or intolerance: tremors, sweating, racing heart or an irritated stomach can be signs of an intolerance to caffeine.

Incidentally, one reacts similarly if too much caffeine has been consumed. Doctors say that 400mg of caffeine per day is the maximum for an adult, but ultimately it depends on things like body weight and your own sensitivity whether you can tolerate caffeine well - or rather decaffeinated coffee. You also need to know that caffeine is also found in other foods such as tea, cola and cocoa.

Decaffeinated coffee is also suitable for people with a tendency to high blood pressure. So everyone who likes to drink coffee a lot and often likes the taste, but has to pay attention to this vital value. If you belong to this group, then read through our article on the effects of coffee on the heart and blood pressure - it tells you what to watch out for.

decaffeination method


It may also be advisable for pregnant women to switch from coffee that contains caffeine to decaffeinated coffee. Although a cup of normal coffee is allowed, provided that the mother-to-be had already drunk it before the pregnancy. You can find more information about coffee during pregnancy here.

Some sources also recommend decaffeinated coffee for athletes or people who are very nutrition-conscious. That said, caffeine isn't as bad as many people think. And did you know that athletes in particular like to drink coffee because the caffeine promotes oxygen absorption in the muscles? Here are some more surprising facts about caffeine.

Final Thoughts

So, is decaf coffee for you? If you are someone who is considering making the switch to decaffeinated coffee, know that you don’t have to compromise the flavor and aroma of your drink if you choose your coffee beans carefully.

It is a fact that not all decaffeination methods result in tasty coffee so if you want to learn more about the different decaffeination processes, have a look at our article about the Swiss Water Process. Happy Brewing!

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