How Does the Decaffeination Coffee Bean Process Work?

Decaf coffee is made by removing caffeine from green coffee beans before roasting, not by finding beans that never contained it. The main commercial methods are the Swiss Water Process, direct solvent extraction, and high-pressure carbon dioxide extraction. Each targets caffeine while trying to preserve the bean's flavor compounds, and each leaves a different trace on the final cup.

The earliest technique dates to around 1820, when Runge identified caffeine as the component disrupting sleep. Large-scale production only arrived in 1903, after Ludwig Roselius found that seawater soaking lowered caffeine levels. Swiss coffee, meanwhile, is a separate style and unrelated to decaffeination, while naturally low-caffeine varieties such as Laurina Bourbon remain scarce and costly.

For those who want to savor coffee yet worry about caffeine disrupting their sleep, decaf coffee is undoubtedly a thoughtful choice. But how exactly is caffeine removed from decaf coffee? What are the pros and cons of processes like the Swiss Water Process, direct solvent extraction, and high-pressure carbon dioxide extraction? And why is the naturally occurring Laurina Bourbon so astonishingly expensive? From the perspective of Front Street Coffee, this article sorts out the historical origins of decaf coffee, standards across different countries, and processing methods, and includes the brewing parameters and flavor description of Front Street's Colombia Huila Decaf coffee beans, helping coffee lovers gain a comprehensive understanding of the pros, cons, and effects of decaf coffee.

Modern people often find themselves in a contradiction: they want to enjoy delicious food but worry about calories; they want to drink coffee but don't want to consume caffeine. As a result, walking into a café and ordering "a latte, decaf, please" is not an uncommon scene. Yet many cafés can only shake their heads helplessly—the vast majority of coffee beans on the market are not low-caffeine varieties, and customers who choose decaf are a minority group, so decaf coffee is indeed not very common in ordinary shops.

You may have heard the term "decaf" often, but do you really understand the decaffeination principles behind it? By what method is caffeine actually removed? Did you know that there is a type of coffee variety that is naturally extremely low in caffeine? Below, Front Street Coffee will answer all these questions about decaf one by one.

Where did decaf coffee come from?

According to Front Street Coffee's research, the great German literary figure Goethe loved coffee but was troubled by difficulty falling asleep after drinking it. So Goethe asked his friend Runge to analyze the components of coffee beans and identify the root cause of the sleep disruption. Around 1820, Runge confirmed that caffeine was the culprit interfering with sleep and worked out a method to remove caffeine, and is thus regarded as the pioneer of decaffeinated coffee.

However, early caffeine extraction techniques were quite limited, and decaf coffee could not be produced on a large scale. It was not until 1903 that German coffee bean importer Ludwig Roselius discovered that once coffee beans were soaked in seawater, their caffeine content dropped noticeably. He immediately organized a team of chemists to develop an extraction process, achieving a key breakthrough in decaffeination technology, and only then could decaf coffee be mass-produced.

What is decaf coffee?

From the name alone, it is clear that decaf coffee is not completely caffeine-free. So just how low can its caffeine content be? Different regions have set their own standards. The European Union stipulates that the caffeine content of roasted coffee beans must not exceed 0.1%, and that of coffee extracts (instant coffee) must not exceed 0.3%.

The U.S. Food and Drug Administration (FDA) standard is that at least 97% of the caffeine must be removed, with only 3% residue allowed, for coffee to qualify as decaf. Converted, this means caffeine must account for between 0.032% and 0.036% of the coffee bean's weight to meet the U.S. decaf standard.

How is caffeine removed from coffee beans?

According to Front Street Coffee's research, there are currently many methods for removing caffeine from coffee beans, most involving water, organic solvents, or carbon dioxide.

Common decaffeination methods include the Swiss Water Process, the direct solvent process, the indirect extraction process, the high-pressure carbon dioxide extraction process, and the mountain spring water process.

[Swiss Water Process] According to information Front Street Coffee has reviewed, the Swiss Water Process first soaks green coffee beans in hot water, and this stage already removes part of the caffeine. The soaking liquid is then filtered through activated charcoal and returned to the coffee beans. This method decaffeinates more thoroughly and requires no chemical solvents, and the soaking liquid can be reused across different batches. The downside is that the coffee loses some of its flavor during the filtration process.

The Swiss Water Process can remove 99.9% of the caffeine, making it the method with the highest decaffeination rate. It is low-cost, easy to operate, and highly efficient, and most of the decaf coffee beans commonly found on the market use this method.

[Direct Solvent Process] The direct solvent process uses chemical solutions such as dichloromethane or ethyl acetate to dissolve out the caffeine. In operation, steam is first used to open the pores of the green coffee beans, then the dichloromethane solvent is added directly to the beans. After the solvent binds with the caffeine, the caffeine-rich solvent is washed away, and finally the coffee beans are steamed again to remove all residual solvent.

Some people worry that long-term exposure to dichloromethane increases cancer risk. After looking into information on dichloromethane, Front Street Coffee found that its boiling point is 39.8°C, so whether through steam or roasting temperatures, it is enough to completely evaporate the dichloromethane. Therefore, there is no need to worry about cancer risks.

[High-Pressure Carbon Dioxide Extraction Process] The high-pressure carbon dioxide extraction process first uses dry supercritical carbon dioxide to extract the aromatic components from roasted coffee beans, then uses water-containing supercritical carbon dioxide to remove the caffeine, and finally returns the previously extracted coffee aromas to the now caffeine-free beans.

Supercritical carbon dioxide has strong penetrating power and low surface tension, allowing it to reach deep inside the coffee beans. This method of decaffeination does not damage the coffee beans, does not change their color, and tends not to extract substances other than caffeine, preserving the beans' original flavor—but it requires a special high-pressure environment to achieve.

So that some friends can enjoy coffee without any burden, Front Street Coffee has brought in a decaf coffee bean processed using the Swiss Water Process.

Front Street Coffee: Colombia Huila Decaf Coffee

Region: Huila, Colombia

Altitude: 1,750 meters

Varieties: Typica, Caturra, Castillo

Processing method: Swiss Water Process

Grade: Supremo

Brewing Parameters

Dripper: Hario V60

Water temperature: 90°C

Dose: 15 grams

Coffee-to-water ratio: 1:15

Grind size: medium-fine (80% passing through a Chinese standard No. 20 sieve)

Brewing method: staged extraction

Bloom with 30 grams of water for 30 seconds, then pour in a thin stream in circles up to 125 grams for the first stage; when the water level drops and is about to expose the coffee bed, continue pouring up to 225 grams and stop; when the water level drops and is about to expose the coffee bed again, remove the dripper. (Timing starts at the beginning of the bloom.) Total extraction time is 2'00".

Front Street's Colombia Huila Decaf has a pronounced black chocolate and nutty flavor on the palate, with caramel sweetness and a good body.

Is there naturally decaf coffee?

Since there is artificially processed decaf coffee, naturally low-caffeine varieties are of course not absent. In 1810, coffee farmer Leroy on Réunion Island (formerly known as Bourbon Island) discovered a Bourbon mutation—Laurina Bourbon. This variety has a lower caffeine content than other Bourbons.

Due to natural disasters, disease, and human factors, Laurina Bourbon was once on the brink of extinction. Later, with the assistance of French and Japanese agricultural experts, Laurina Bourbon was successfully revived. Its yield is extremely low, and coupled with strong market demand, in 2007 Laurina Bourbon even sold for as much as 4.3 yuan per gram, even more astonishing than Panama Geisha.

What are the benefits of decaf coffee?

Caffeine is actually the largest source of antioxidants in the Western diet. Antioxidants can reduce oxidative damage and may help prevent conditions such as heart disease, cancer, and type 2 diabetes.

Besides antioxidants, decaf coffee also contains small amounts of nutrients. One cup of decaf coffee can provide 2.4% of the recommended daily intake of magnesium, 4.8% of the recommended intake of potassium, and 2.5% of niacin, as well as vitamin B3.

However, due to genetic differences, some people are very sensitive to caffeine, and even a small cup of coffee can keep them awake all night. Decaf coffee happens to solve this problem, allowing these people to taste coffee as well.

For more specialty coffee beans, please add the private WeChat of Front Street Coffee, WeChat ID: kaixinguoguo0925

The above content is compiled by CoffeeHunters, a coffee news website.