The Story and Processing Methods of Decaf Coffee Beans - Flavor Characteristics, Pros and Cons of Decaf Coffee

【Coffee is delicious, but remember not to overindulge】refers to the fact that coffee contains caffeine. FrontStreet Coffee reminds you that appropriate caffeine can boost energy and eliminate fatigue. However, excessive caffeine can lead to caffeine intolerance symptoms. Decaf coffee removes most caffeine while preserving the flavor of coffee beans, making it suitable for people who enjoy black coffee but are intolerant to caffeine. Therefore, decaf coffee has also appeared on the market to satisfy the taste buds of coffee enthusiasts.

Origin and Development of Decaf Coffee Beans

When it comes to decaf coffee, we must mention the story of Goethe and Runge. As a literary creator, Goethe drank large amounts of coffee daily. However, due to his inability to metabolize caffeine quickly, he often suffered from insomnia. Out of desperation, Goethe sought help from his friend Runge, who was a chemist, hoping he could make coffee less potent.

In 1898, Runge finally fulfilled expectations by successfully discovering the caffeine component in coffee beans, solving the mystery of Goethe's insomnia after drinking coffee. Since the late 19th century, scientists have continuously researched how to inhibit the effects of caffeine, wanting to remove caffeine components while preserving other substances in coffee. In 1903, coffee merchant Ludwig Roselius first commercialized caffeine-removed beans; this technology gradually matured after continuous improvement. However, the decaffeination process must start with raw coffee beans, and decaffeinated coffee beans are difficult to roast, with significantly diminished aroma. So how are decaf coffee beans extracted?

Chemical Solvent Extraction Method (Traditional Method)

Chemical solvents are used to extract caffeine, divided into direct and indirect methods.

The direct solvent treatment method uses chemical solutions such as dichloromethane and ethyl acetate to dissolve caffeine. First, steam opens the pores of raw coffee beans, then dichloromethane solvent is directly added to the coffee beans. After the solvent fuses with caffeine, the caffeine-filled solvent is washed away, and the coffee beans are steamed again to remove all residual solvent.

Since the use of dichloromethane is suspected to increase cancer risk with long-term exposure, there are concerns about using it as a solvent. However, the FDA actually limits dichloromethane content in decaffeinated coffee to 0.001%, which is even lower in practice, with minimal side effects.

The process using ethyl acetate as a solvent is the same. Ethyl acetate typically comes from sugarcane, so when used, the direct solvent method is sometimes called the sugarcane decaffeination method. Decaffeination in Colombia usually uses this method. However, ethyl acetate is a highly flammable substance, making it more dangerous.

Coffee beans do not come into direct contact with the solvent. However, this method has generally been discontinued for decaffeination.

Swiss Water Process (SWP)

This method was invented in 1933 and commercialized in the 1980s, registered as the Swiss Water Process. This treatment soaks raw coffee beans in hot water; during the soaking stage, caffeine is already partially removed. The soaked solution is then filtered through activated carbon, and finally the solution is poured back into the coffee beans. This series of steps more effectively removes caffeine. Besides not requiring chemical solvents, the soaked solution can be reused in different batches of processing, but coffee still loses flavor during the filtration process.

This method can achieve a caffeine removal rate of 99.9%, making it the method with the highest caffeine removal rate.

Mountain Spring Water Process

Very similar to the Swiss Water Process, this uses another special water - water taken from glaciers to extract caffeine. The company Descamex states they use a special filtration device to remove caffeine. After treatment, a water-based solution without caffeine is obtained, which also dissolves coffee solids and can be reused in the decaffeination process.

Supercritical Carbon Dioxide Process

This treatment method first allows coffee beans to absorb water and swell, with caffeine molecules in a loose state within the beans. Liquefied carbon dioxide is added and creates pressure greater than 100 atmospheres in water. Carbon dioxide is highly selective, dissolving caffeine without "harming" the carbohydrates and proteins in coffee beans, ensuring the coffee flavor is not destroyed. The liquid carbon dioxide that carries away caffeine can also be reused after removing caffeine.

Coffee decaffeinated using carbon dioxide has lower burden on the human body, and according to research, this method extracts more caffeine than the direct solvent method, while this method costs much more than the direct solvent method.

Advantages and Disadvantages of Decaf Coffee

Caffeine is actually the largest source of antioxidants in the Western diet; decaf coffee usually contains similar amounts of antioxidants as regular coffee, but they may be as low as 15%. This difference is likely due to the small loss of antioxidants during the decaffeination process. Therefore, more and more people are choosing decaf coffee because it has antioxidant effects while not affecting sleep.

The main antioxidants in regular and decaf coffee are hydroxycinnamic acids and polyphenols. Antioxidants are very effective at neutralizing active compounds called free radicals. This can reduce oxidative damage and may help prevent diseases such as heart disease, cancer, and type 2 diabetes.

In addition to antioxidants, decaf coffee also contains small amounts of some nutrients. A cup of brewed decaf coffee provides 2.4% of the recommended daily magnesium intake, 4.8% potassium, and 2.5% niacin, or vitamin B3. This may not seem like many nutrients, but if you drink 2-3 cups (or more) of coffee daily, these amounts quickly add up.

Considering the above decaf coffee processing methods, FrontStreet Coffee believes that decaf coffee doesn't taste bad due to the processing. This is because most decaf coffee selects some cheap, commercial-grade coffee beans as raw materials. Modern decaffeination technology is quite complex, and in most cases, companies producing decaf coffee naturally prefer some high-caffeine coffee bean varieties (such as Robusta beans) when selecting raw materials. Before decaf coffee beans undergo decaffeination, the coffee beans were already not tasty. Like other coffee beans sold in coffee shops, if decaf coffee beans start with high-quality Arabica coffee beans from the raw bean stage, then even after decaffeination, decaf coffee can still have very good performance.

Speaking of so many decaf coffee processing methods, FrontStreet Coffee has a decaf coffee bean from Colombia's Huila that uses the Swiss Water Process. This method can achieve a caffeine removal rate of 99.9%, making it the method with the highest caffeine removal rate.

The color of raw coffee beans after decaffeination will appear dark green.

After roasting, the beans will appear more oily and shiny after a few days. The reason may be that during the decaffeination process, coffee beans need to be soaked in hot water to release caffeine, then undergo drying treatment. During this process, the fiber structure of coffee may have changed, causing oils to be more easily released when roasting reaches medium-dark levels.

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