How is coffee decaffeinated? The 4 processes explained

The coffee bean has a tough life. It starts as a cherry on a plant, then it’s picked and dried, and finally, it’s ground up to make coffee. It goes through a lot of pain and suffering, but it’s all worth it in the end. Thanks, coffee bean!

But even still, we’re not satisfied. Sometimes this unique bean gives us too much energy, and we can’t handle it. That’s when we need to decaffeinate it.

But how do we go about removing one of the primary compounds that make coffee, caffeine? Surely it can’t be easy.

Well, there are actually four main ways to decaffeinate coffee. But before we answer the question “How is coffee decaffeinated?”, let’s start with a bit of an overview.


How is coffee decaffeinated

What is decaffeination, and how does it work?

The removal of caffeine from coffee in order to make it easier to drink without the jitters or other negative consequences is known as decaffeination. Many different methods are used to decaffeinate coffee beans, but they all work by exploiting their particular chemical properties.

Water or carbon dioxide are used to extract caffeine through several decaffeination processes. Others use solvents like methylene chloride or ethyl acetate. The Swiss water process is a decaffeination method that uses only water and charcoal filters.

Alternatively, the indirect solvent process uses a solvent (usually methylene chloride) to remove caffeine from coffee beans.

Ultimately, decaffeination allows us to enjoy coffee’s rich flavor and aroma without unwanted aftereffects like heart palpitations and nervousness.


How is coffee decaffeinated green coffee beans

Coffee beans are green when decaffeinated

The coffee bean isn’t actually a bean, it’s a seed, and it’s green when harvested. The roasting process turns them brown. Decaffeination happens before they have been roasted.

The green coffee beans are first put in water. Then, the water is removed and replaced with a solvent. The beans are rinsed, and the solvent is evaporated off.

This process can be done multiple times to remove as much caffeine as possible from the coffee beans.


The four main types of decaffeination processes

  • Direct-solvent process: The beans are soaked in a solvent (usually methylene chloride) to remove the caffeine.
  • Indirect-solvent process: The beans are soaked in water, and then the water is passed through a chamber containing the solvent. The caffeine dissolves into the solvent, which is then removed and the process repeated.
  • Carbon dioxide process: The beans are placed in water, and then the water is passed through a chamber containing carbon dioxide. The caffeine dissolves into the carbon dioxide, which is then removed and the process repeated.
  • Swiss water process: The beans are soaked in water to remove the caffeine. The water is then passed through a charcoal filter to remove the caffeine.

Each decaffeination method has its own set of pros and cons, so it’s essential to understand the difference between them before choosing which coffee to buy. Let’s take a closer look at each type.


How is coffee decaffeinated

How the direct-solvent process works

In the direct-solvent process, the coffee beans are in contact with a chemical that removes the caffeine.

The first step is to steam the beans for about half an hour. This opens up their pores and makes them more responsive to a solvent.

Then, they are rinsed repeatedly for the next ten hours. This is typically done with methylene chloride or ethyl acetate. These chemicals bind to the caffeine and remove it from the beans.

Some may worry that the use of chemicals could leave traces of them in the final cup of coffee. However, it’s worth noting that coffee is usually roasted at 400+ degrees and brewed at around 200 degrees. This makes it highly unlikely that any traces of chemicals would remain in the final cup of coffee.


How is coffee decaffeinated

How the indirect-solvent process works

The difference between the indirect and direct solvent processes is that, in the indirect process, the beans never come into contact with the solvent.

Indirect-solvent decaffeination was developed in Switzerland in the late 1970s and has become the most popular method of decaffeination used today. It is also sometimes called the “Mountain Water Process” because it was developed in the Swiss Alps.

This method involves soaking the beans in hot water to extract the caffeine and other coffee components. The water is then transferred to another tank, where it is treated with a solvent.

The solvent only consumes the caffeine, leaving the oils and flavor molecules in the water. The solvent-caffeine mixture is then skimmed off the top of the water and returned to the original tank with the beans.

The beans then reabsorb the flavors and proteins from the water, resulting in a cup of coffee that is 99.99% caffeine-free.


How is coffee decaffeinated

How the Swiss water process works

The Swiss water method is the only decaffeination technique that does not employ any chemicals, making it the most natural style of decaf. This method was pioneered in 1933 but wasn’t introduced to the market as a commercially viable process until 1988.

The beans are first steamed to release the caffeine and make it more accessible. Then, they’re soaked in water that has been over-saturated with coffee compounds (from an initial batch of beans).

The caffeine is drawn away from the beans into the water while the coffee’s flavor compounds stay intact.

Finally, the water goes through an activated charcoal filter, which captures the larger caffeine molecules but allows smaller oil and flavor molecules to pass through. This results in decaffeination while maintaining the coffee’s original flavor as much as possible.

The final step is a slow drying phase. Drying can be done using either heat or air, but sun-drying is the slowest and most gentle method.

This decaffeination process can be applied to both Arabica and Robusta beans but is more commonly used for specialty coffees like Arabicas.

The Swiss water method can be more time-consuming and expensive than other decaffeination processes, but it’s also the only one that doesn’t involve using any chemicals. This makes it an excellent option for people who want to avoid consuming any traces of chemicals in their coffee.

One downside of the Swiss water process is that it can strip away some of the coffee’s natural oils, which can impact the flavor.


How is coffee decaffeinated

How the carbon dioxide process works

The carbon dioxide process of decaffeination is a relatively new method, first developed in 1967 by Kurt Zosel.

The beans are first steeped in water and then placed in a stainless steel container (also known as the extraction vessel). Pressurized CO2 is injected into a sealed container at 1000 pounds of pressure per square inch to extract the caffeine.

The carbon dioxide solvent dissolves and draws only the caffeine out of the coffee, leaving behind all of the flavor molecules. The caffeine-packed carbon dioxide is then moved to another container, known as the absorption chamber, where the pressure is released, and the carbon dioxide returns to a gaseous state, and only the caffeine remains.

The caffeine-free carbon dioxide is placed back into the pressurized tank to be used again. This process can be repeated multiple times until the coffee beans are 99.99% decaffeinated.

The carbon dioxide process is considered to be one of the most gentle methods of decaffeination and results in coffee that retains much of its original flavor. However, it is also one of the most expensive methods due to the cost of the equipment and the high pressure required. Consequently, this method is not widely used on a commercial scale.


How is coffee decaffeinated

Does decaf coffee taste bad?

In general, decaf coffee does not taste bad. However, the quality of the coffee can vary depending on the type of beans used and the decaffeination method employed.

The best way to ensure that you’re getting a good cup of decaf is to buy specialty Arabica beans that have been decaffeinated using the Swiss water method. These coffees tend to be the most expensive but also the best tasting.

If you’re on a budget, look for coffee beans that have been decaffeinated using the indirect-solvent or carbon dioxide methods. These coffees will still have good flavor, although they may not be as rich and complex as Swiss water decaf. Coffee decaffeinated with direct or indirect methods may not be clearly labeled, so be sure to ask your barista or retailer about the process used.

When it comes to decaf, the quality of the beans and the decaffeination method make all the difference. Do some research and be willing to pay a bit more for a great cup of coffee. You won’t be disappointed.


How is coffee decaffeinated

What are the benefits of decaffeinated coffee?

Decaffeinated coffee has all of the benefits of regular coffee, except it lacks most of the caffeine. Decaffeinating coffee beans removes about 97% of the caffeine.

This means that you can enjoy all of the flavor and aroma of coffee without the side effects of caffeine, such as jitters, anxiety, and trouble sleeping.

Decaf coffees are also a great option for people who are sensitive to caffeine or have medical conditions that preclude them from consuming it. Pregnant women and young children, for example, should avoid caffeine.

Green coffee extract, which is made from unroasted coffee beans, is also very high in caffeine. If you’re looking for a decaf option that still has some health benefits, look for a green coffee extract that has been decaffeinated.


What are coffee alternatives?

If you’re looking for a caffeine-free alternative to coffee, plenty of options are available.

Herbal teas, such as chamomile, lavender, and ginger tea, are all naturally caffeine-free and can be enjoyed hot or iced.

You can also find many types of decaf tea on the market. These teas have had the majority of their caffeine removed but still retain some flavor.

Another option is to make your own cold brew coffee at home using decaffeinated beans. This will give you all the flavor of regular cold brew without the caffeine kick.

There are also several brands of caffeinated seltzer water on the market that can be enjoyed in place of coffee or tea.


Final Thoughts

So, there you have it – the four main ways coffee beans are decaffeinated. Each process has its own advantages and disadvantages, so it’s important to choose a method that suits your needs and preferences.

Do you like your coffee strong and full of caffeine? The carbon dioxide process is probably not for you. However, if you’re looking for a gentle, flavor-rich cup of decaf, the Swiss water process is hard to beat.

No matter which method you choose, be sure to buy quality beans from a reputable source. This will ensure that you get the best possible cup of decaf coffee every time. Happy decaffeinating!

Kris Silvey

I've been drinking coffee my entire life, from a little boy stealing coffee off the counter to an adult (who still steals his wife's coffee occasionally). I'm passionate about exploring the world of coffee and finding another great roast to experience.