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Do You Want To Know How Are Coffee Beans Decaffeinated? Read This Quick Guide


Are you a coffee lover? Enjoy your daily cup of Joe, but looking for ways to reduce your caffeine intake? Well, decaffeinated coffee can be a great alternative. But do you know how coffee beans are decaffeinated?

This guide will provide you with an in-depth look at the various methods used to extract caffeine from coffee beans. It will explore key considerations when deciding on which method to use as well as each method’s pros and cons.

Additionally, this guide will discuss how green or roasted beans are best suited for certain decaffeination processes and why specific regions prefer particular processes over others.

By the end of this guide, you’ll have a comprehensive understanding about when and why different areas opt for different types of decaffeination methods. So let’s get started!

Common Decaffeination Processes

Coffee is a beloved beverage around the world, but for some, the caffeine content can be too much. To make the drink more accessible, coffee beans can be decaffeinated. Over the years, different processes and techniques have been developed to decaffeinate coffee beans. In this article, we will be exploring the most common decaffeination methods available:

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  • Solvent Process
  • Swiss Water Process
  • Carbon Dioxide Process
  • Direct Process

Chemical Solvent Process

The chemical solvent process is the most common way of decaffeinating coffee beans. It is based on the fact that caffeine is slightly soluble in hot water and highly soluble in certain solvents like chlorinated hydrocarbons.

In the chemical solvent process, green coffee beans are first soaked in hot water to extract some of their caffeine. The water-caffeine solution and the beans are then mixed with a solvent such as methylene chloride or ethyl acetate. The mixture is agitated to ensure that all the caffeine molecules attach to the solvent, which can then be easily removed from the beans and discarded. Once this process is completed, the beans are dried and ready for roasting.

Variations of this method may use liquid carbon dioxide or a combination of water and steam instead of the chemical solvent to scrub caffeine from whole coffee beans. Other processes like super critical carbon dioxide use pressurized liquid CO2, but it requires expensive equipment so it’s not practical for large roasters who process thousands of pounds of green coffee daily. Both methods achieve similar results but take longer than conventional chemical decaffeination processes and may lead to subtle flavor changes in roasted coffees when compared against those treated with solvents.

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Water Process

The water process, also known as the Swiss Water Process, is a chemical-free decaffeination method for coffee beans. This process begins by soaking unroasted coffee beans in hot water. This removes the caffeine from the beans as well as some of their flavor components.

The solution is then strained and passed through an activated carbon filter which absorbs the caffeine particles while allowing most of the original flavor molecules to pass through and be collected in a solution of green coffee extract (GCE). The GCE contains most of the coffee’s essential oils, acids and subtle aromas that give coffee its unique taste.

The green coffee extract is then reused to decaffeinate new batches of unroasted beans. These new beans are soaked in the GCE which extracts most of the caffeine but leaves much of the original flavor molecules intact on the bean. This cycle continues until a satisfactory level of decaffeination has been achieved. The result is a cup of pleasant flavored decaffeinated coffee without the use any chemicals.

Water processed coffees generally have good aromatic character, body and flavor when compared with other commonly used methods such as:

  • chemical solvents
  • direct contact with supercritical carbon dioxide (CO2)

Some companies boast that their water processes create up to 99% caffeine free coffees; however this varies from manufacturer to manufacturer based on how well they implement their process and whether they prefer slightly caffeinated brewing solutions for some specialty flavored coffees.


Carbon Dioxide Process

The carbon dioxide (CO2) process is a decaffeination method that uses liquid or supercritical CO2 to extract the caffeine from coffee beans. The supercritical CO2 is created by raising the pressure and temperature of CO2 gas until it takes on properties between a gas and liquid, allowing it to dissolve caffeine molecules while leaving most of the flavor intact. It also eliminates any odor or taste associated with other decaffeination methods. This means that coffee beans decaffeinated using the CO2 process retain the same characteristic flavors found in coffee beans not treated with this method.

The process starts when green coffee beans are loaded into a stainless steel tank filled with water, which then is heated up to 195°F (90°C). Once it reaches this temperature, pressurized CO2 is released into the tank where it begins to circulate around and within each bean, slowly dissolving caffeine molecules. This can take up to 10 hours for this process to be completed.

Once finished, a centrifuge separates the solution containing extracted caffeine from the now decaffeinated coffee beans and the remaining liquid is returned back into its original state by removing heat and pressure. The result is roasted beans with 97% of their original caffeine content removed without leaving any residual taste or smell behind.

Swiss Water Process

The Swiss Water Process (SWP) is an innovative decaffeination process that uses water from the Snow Mountain regions of the Swiss Alps and several of their patented technologies to decaffeinate coffee without chemicals. This process is trusted by many specialty and craft roasters since it preserves the flavor of the coffee while removing 99.9% of its caffeine content.

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The beans undergo a number of steps before finally reaching their decaffeinated state. First, they are soaked in hot water until they become soft and pliable, then passed through a proprietary carbon filters with millions of pores to absorb heavy molecules like caffeine but small enough to let through flavorful compounds like oils, sugars, and proteins. The beans then re-emerge from the filter unchanged in flavor yet much less caffeinated than before.

Finally, the beans are dried with warm air then sent for roasting where any remaining traces of caffeine can be removed through roasting time manipulation. Notably, this method does not use any chemicals in decaffeination and hence none remain behind even after multiple rounds of washing and filtration processes making it an appealing choice for customers who want to avoid adding potentially harmful ingredients into their bodies when drinking coffee or tea beverages made with these beans.

Pros and Cons of Each Process

There are different methods and techniques used to decaffeinate coffee beans. These processes vary and come with their own set of pros and cons. In this guide, we’ll take a closer look at each method to help you decide which one is the best for your coffee needs.

From chemical-based processes to carbon dioxide based processes, we’ll explore the strengths and weaknesses of each technique:

Chemical Solvent Process

The Chemical Solvent Process is one of the most common methods used to decaffeinate coffee beans. This method uses either methylene chloride or ethyl acetate, two mild chemical solvents that dissolve and extract caffeine from the coffee beans.


  • It is the most efficient and cost-effective decaffeination process.
  • Results in a milder flavor that is more similar to non-decaffeinated coffee than other processes.
  • Leaves fewer residual levels of solvents than other processes such as Supercritical Fluid Extraction.


  • Require rigorous monitoring of temperature and pressure by trained technicians in order to ensure that the levels of solvents don’t exceed safe limits.
  • May alter some biochemical properties of the beans, leading to some flavor loss.

Water Process

Water Process is a decaffeination method that uses hot water to extract caffeine and flavor-producing compounds from green coffee beans before they are roasted. It is one of the oldest and most natural methods of decaffeination, as it doesn’t use chemical solvents or involve excessive heat or pressure.


  • This is an all-natural process that produces a final product that preserves more of the bean’s flavors than other decaffeination methods.
  • It is suitable for larger production runs, making it ideal for commercial scale roasting operations.
  • Coffee beans processed by this method remain in good condition with minimal damage to the physical makeup, such as cracks and splits.


  • This process requires a large volume of water and can take up to 10 hours to complete, so it isn’t very efficient in terms of time and resources compared to other more chemical approaches.
  • The cost can be prohibitive for many small businesses because the equipment needed to carry out this method is expensive.

Carbon Dioxide Process

The Carbon Dioxide Process, or CO2 process, uses liquid carbon dioxide to extract caffeine from the green coffee beans. It is considered one of the safest and most effective methods of decaffeination as it does not require the use of harsh chemicals, while still yielding a high quality and flavorful cup of coffee.

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The process begins with green coffee beans that have been carefully inspected and selected for use. The beans are then placed into solvents in order to separate out the natural oils from the caffeine. The solvent concentration is closely monitored during this step so that both components remain in perfect balance.

Once separated, the beans are immersed in liquid carbon dioxide for about 10 hours which acts as a powerful solvent to release caffeine molecules from the bean itself without removing any essential oils or flavor compounds. The resulting solution is then filtered through a series of meshes that allows for precise extraction and removal of all remaining caffeine molecules, leaving only naturally decaffeinated beans behind.

The Carbon Dioxide Process stands out from other methods due to its ability to preserve more original flavors while at the same time removing 97-99% of all caffeine content with minimal risk or chemical usage. This makes it particularly attractive for specialty roasters who want to offer decaffeinated options without sacrificing taste or quality. The main drawback is that this method can be expensive and time-consuming when compared with other processes such as chemical solvents or water-based decaffeination used by many large-scale commercial brands on a larger scale. However, knowledge and application of this process can produce excellent results when applied correctly– making it well worth consideration by those seeking exceptional flavor with every cup!

Swiss Water Process

The Swiss Water Process is a completely chemical-free decaffeination method. It uses only water from the southwestern region of British Columbia, called the “Coast Mountains,” as well as proprietary carbon technology to remove caffeine from coffee beans in a way that preserves their original flavor.

During this process, green beans are soaked and passed through a proprietary heated water solution. Through osmosis, unpartitioned caffeine molecules join with other molecules to pass over certain filters while oils, oils and other compounds remain behind in the green beans. The result is 99.9% caffeine-free coffee that has retained its original flavor profile.


  • No chemicals used
  • Retains original flavor
  • Coffee is 99.9% caffeine free


  • Expensive process compared to other methods
  • Less scientific control over caffeine extraction than other methods


In conclusion, coffee beans are decaffeinated through various processes depending on the desired application. From Swiss Water Decaffeination to Supercritical Carbon Dioxide Extraction, there is no one-size-fits-all when it comes to decaffeinating coffee beans. Regardless of the process chosen, it’s important to understand the pros and cons of each instance in order to get the best possible result. While there may be variations in taste or quality due to the process chosen, thanks to current scientific advances, coffee drinkers can enjoy a cup of coffee without having to worry about its caffeine content.

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About the author


Samuel is a coffee lover and a writer. He's travelled extensively throughout Southeast Asia and has soaked up the sun, the culture, and of course - the coffee. He loves to write about his experiences, and he hopes to travel even more in the future.

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