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How is decaf coffee made? Inside the process that takes caffeine out

The journey from raw beans to decaf

coffee bean
Anastasia Zhenina / Unsplash

All coffee beans are naturally caffeinated in their raw state. But, thanks to a discovery by Ludwig Roselius in 1903, we can now enjoy decaf coffee as an alternative, perfect for enjoying the flavor of coffee without caffeine. The question of “regular or decaf?” is a familiar one, but less often do we think about how decaf coffee is made. Before it is roasted and bagged for your enjoyment, decaf coffee beans go through a lengthy process to become decaffeinated. Below, explore some insight into the journey of your decaf coffee beans before it gets to you.

The origins of decaf coffee

Cup of coffee with beans on a table
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German coffee merchant Ludwig Roselius first created the concept of coffee without caffeine by accident. After his father passed away from consuming too much caffeine, he discovered that coffee beans immersed in seawater lost their caffeine content. Known as the “Roselius” process, this method involved using a saltwater solution and benzene to remove caffeine from coffee beans.

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This method is no longer used today due to various concerns about benzene. However, the discovery of this initial method served as an important stepping stone for the birth of decaf coffee and gave Ludwig Roeselius his nickname as the “father of decaf coffee.” Instead, there are four modern-day methods used today to make decaf coffee.

How decaf coffee is made

A cup of coffee beside spilled coffee beans.
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Multiple approaches are used to make decaf coffee today, which can be broken down into two main categories: solvent-based and non-solvent-based. The most common way to decaffeinate coffee beans is the European method, an indirect solvent method that involves warming and soaking green coffee beans. The method includes:

  1. Steaming green coffee beans to open pores and make caffeine more accessible.
  2. Rinsing coffee beans with methylene chloride, which bonds to caffeine to remove it.
  3. Removing liquid caffeine solution that is formed.
  4. Drying and roasting the decaf coffee beans at 400 degrees Fahrenheit or more.

Solvent-based methods

A direct or indirect solvent method can be used within the category of solvent-based methods. Though the indirect solvent method mentioned above is the most common, many coffee manufacturers also use direct solvent-based methods. This method first soaks the beans in a chemical solvent such as methylene chloride or ethyl acetate. After this, the beans are then steamed away to remove any remaining traces of solvent.

Non-solvent based methods

Two widely known non-solvent-based methods are used to make decaf coffee. The first method is the Swiss Water Method. This method gently removes caffeine by soaking green coffee beans in water for several hours. This creates a solution known as Green Coffee Extract (GCE). This solution passes through a carbon filter to remove caffeine molecules, allowing the beans to retain flavor and oils.

The other popular non-solvent-based method is known as the CO2 method. The CO2 method involves soaking coffee beans in water and placing them in an extraction vessel. Liquid CO2 is forced through the coffee under high pressure to extract the caffeine from the beans. Both methods use natural methods and do not use any chemicals to remove the caffeine from the coffee beans.

Are all decaffeination methods safe?

Coffee beans
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According to the National Coffee Association, all methods used to create decaf coffee are equally safe. Although all decaf coffee is safe to consume, many health enthusiasts argue that non-solvent-based decaffeination methods, such as the Swiss Water method, are ideal because they do not use harmful chemicals.

Additionally, most coffee connoisseurs agree that decaffeinated coffee using non-solvent-based methods produces better-tasting decaf coffee. This is because the chemicals used in solvent-based methods can slightly alter the taste of the coffee beans and, thus, your cup of coffee.

Many decaf coffee drinkers haven’t given much thought to how decaf coffee is made and might not even be sure what method was used to manufacture the decaf coffee they drink daily. To discover what method was used, you can always check the packaging of your decaf coffee or check directly with the brand. Terms like “chemical-free” or “solvent-free” can be misleading for consumers too.

I was initially skeptical, but I could taste the difference once I compared two cups of decaf coffee made with two different methods. If you’re a coffee drinker who believes the usual “decaf coffee has no taste” myth, I recommend retrying a higher-quality decaf coffee made with a non-solvent-based method.

Is decaf coffee fully caffeine-free?

Coffee farming
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Regardless of how decaf coffee is made, decaf coffee is not 100% caffeine-free. Most methods remove between 97 and 99% of the caffeine from green coffee beans, leaving about 1 or 2 mg remaining in each 8-ounce cup of decaf coffee. The Swiss Water method removes the most caffeine of all four decaffeination methods, removing about 99.9% of the caffeine within the beans. Either way, there is so little remaining caffeine in any decaf coffee that you are unlikely to feel any of the effects of caffeine.

Emily Caldwell
Emily is an accomplished freelance journalist with over seven years of experience in food, beverage, health, fitness, and…
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