Decaffeinated Coffee: 3 Ways It’s Made

Written by: Garrett Oden

decaffeinated coffee

Death before decaf!

Actually, we don’t really think that way here at JavaPresse.

You see, there’s some really good decaffeinated coffee out there, but there’s also some utter garbage (sad). If you want to enjoy a mug when you know you don’t need the caffeine, decaf can be your delicious friend.

But don’t buy any decaf beans without reading this first.

You should know the three main processes that coffee is decaffeinated.

  • One common method is expensive
  • One common method is very controversial
  • And the last common method is perfectly safe and tasty

Yeah, buying decaf coffee that’s been processed the right way makes a BIG difference.

Let me walk you through the three main processes so you can easily tell what to avoid and what could be super delicious.

Read: Skip The Coffee Aisle, Here's How To Find The World's Best Coffee

Similarities In All Three Methods

Decaffeination always happens when the coffee is green (unroasted). All methods include soaking the beans in water at some point. This is what causes the beans to swell so that the caffeine can be extracted.

The real differences are in the solvent that the methods utilize to take out the caffeine without destroying all the other hundreds of flavor compounds that surround the caffeine.

With that in mind, let’s get into some specific processes.

The Carbon Dioxide Method

Here’s a fun fact I don’t completely understand:

When under immense pressure, CO2 behaves like part-gas, part-liquid.

Honestly, I can’t really imagine what that looks like.

Read: The Easy Guide to Coffee Bean Storage

Facilities that use the CO2 method exploit this odd middle state. The beans are soaked in this half-liquid half-gas CO2, which selectively grabs out the caffeine but leaves just about everything else inside the bean.

The CO2 is separated from the caffeine molecules a couple of ways.

  • Charcoal Filtering. The middle state carbon dioxide is forced through a fine charcoal filter that traps the caffeine but allows the CO2 to pass through.
  • Gas and drop. The CO2 is pumped into an absorption chamber where the CO2 returns to a gaseous state and rises to another chamber. The caffeine is left in the absorption chamber.

For the most part, the flavors are left in the beans, though most people believe there’s a small drop in flavor quality.

This process is expensive, so most companies that use it are decaffeinating large batches of low-grade decaf, unfortunately. While there’s hope for this process in the specialty coffee world, it’s not super common yet.

Read: 5 Ways To Make Your Coffee More Eco-Friendly

The Solvent Method

The solvent method uses one of two chemicals that have not-so-great reputations.

  • Ethyl Acetate. Found naturally in ripe fruits, though artificially created in a lab for use in the decaffeination process.
  • Methylene Chloride. Considered by some as unfit for consumption, but the process leaves virtually no trace in the coffee beans.

These two chemicals bond to caffeine quickly, speeding up the decaf process.

how decaf coffee is made

In the traditional solvent method, the beans are steamed to open up their pores. They’re then mixed with one of these two chemicals, which bond to the caffeine only. The beans are steamed again to remove the solvent/caffeine, are dried, and finally sold to roasters.

However, a more modern solvent method has evolved.

In this method, the green coffee is soaked in near-boiling water for a few hours. The water is then transferred to another tank where the solvents are mixed in. Eventually, the caffeine and solvent are skimmed off the top of the water. The beans are returned to the first tank to resoak the flavor water.

Read: Should You Store Your Coffee Beans In The Freezer?

This is the oldest method for decaffeinating coffee and it’s widely considered the least quality-focused.

The flavor of the coffee is often compromised by the chemicals and the beans tend to not soak up all the flavors they released into the hot water.

The Big Controversy: Health Concerns

This is where things get hairy.

This method used to use other solvents that weren’t so healthy.

One of the most common solvents in the 1970’s, trichloroethylene, was discovered to be a “Cancer Alert” chemical by the National Cancer Institute. Since it wasn’t clear how much was left in the coffee, the solvent fell out of use.

Read: 10 Gifts For The Coffee Connoisseur

It’s likely that the trichloroethylene was roasted away completely, though nobody really wanted to take that chance. And can you blame them?

The modern solvents, ethyl acetate and ethylene chloride, are used in such low amounts that they pose virtually zero health risks. And even if any of these molecules survive in the bean after decaffeination, they’ll surely evaporate away before you brew the beans (they’re volatile).

However, the use of these chemicals produces waste that’s not generated with the CO2 method or the next method.

The Swiss Water Method

The Swiss Water decaf method is the only fully organic method. It uses no chemical solvents other than water itself. No carbon dioxide, no lab-made chemicals, only water.

This method is a patented process by Coffex, a coffee company in Switzerland, though the actual processing happens in Canada.

In this method, the green coffee beans are soaked in warm, pressurized water. The contents of the beans (caffeine, oils, sugars, beyond) are released into the water as the pores of the beans open up. This big batch of brewed green coffee extract is forced through an activated charcoal filter, which traps the caffeine but lets everything else through.

The now flavorless green coffee is discarded and new beans are added. The green coffee extract is added to these beans. The caffeine is extracted like normal, but the sugars, oils, and other flavor compounds remain in the beans (since the green coffee extract they’re soaking in is already dense with those compounds).

Read: Searching For Certified Organic Coffee - Is It Worth It?

Swiss Water decaf coffee has become the specialty coffee standard. Though it’s a little more expensive than using a chemical solvent, it’s clean and does a good job of taking out caffeine while preserving flavors.


And there you have it: the three main ways decaf coffee is made:

  • The effective but expensive CO2 method
  • The questionable, but cheap chemical solvent method
  • And the pricy, yet quality-centric Swiss Water method

I think you can guess which method we’re fans of.

You can get your hands on some stellar Swiss Water decaf coffee via our Coffee Club. It’s 99.9% caffeine-free, is heavy-bodied, and has rich notes of baker’s chocolate and sweet caramel. Want some?