How Is Decaf Coffee Made? A Deep Dive Into Solvent & Water Processed Methods

The word “decaf” evokes an emotional response from many. For the veteran caffeine addict, decaf is an afront to all that is good and right in the world of coffee (am I right?). For others it may be the only way to still enjoy the coffee experience, per doctor’s orders. But then there’s the rest of us, somewhere in the middle of enjoying the additional perk of caffeine and a desire to fall asleep before it’s time to get up again. 

Whatever camp you’re in, decaffeinated coffee is a thing, and it can even be a good thing! The days of poor-quality greens over-roasted to imperfection are almost gone. At Bugle Call Coffee, we approach our decaf with the same care and attention we do our other single origin offerings. Thankfully, the industry as whole has upped their game in providing higher quality options for roasters, and ultimately consumers, to enjoy. 

☕ What Is Decaf Coffee, Really?

Decaffeinated coffee is simply coffee that has had at least 97% of its caffeine removed. But how that caffeine is removed makes all the difference in flavor, quality, and perception. Let’s break it down into the two primary decaffeination methods: solvent-based and water-based.

“But how is decaf made?” Glad you asked! Below are two generally accepted methods: solvent processing and water processing. 

🔬 Solvent-Based Decaffeination

Let’s start with everyone’s favorite fear, the chemical/solvent process. There are basically two approaches using the solvent method: direct, and indirect. 

Direct Solvent Process

1. Green coffee beans are steamed to open their pores.

2. They are washed in ethyl acetate or methylene chloride, which bonds to the caffeine.

3. The beans are steamed again to remove residual solvent.

4. Finally, they are dried and ready for roasting.

Indirect Solvent Process

1. Beans are soaked in hot water to extract caffeine and flavor compounds.

2. The water is separated and treated with a solvent to remove caffeine.

3. The decaffeinated water—still full of flavor—is returned to the beans.

4. The beans reabsorb the flavors and are then dried.

Regardless of the method used, it is extremely unlikely that any of the chemical solvent actually makes it into the cup of coffee. Coffee beans are generally roasted past 400 degrees Fahrenheit, essentially vaporizing any residue that may be left in the green beans after the decaffeination process (which was already very small). Still, the very personal choice to avoid these coffees have merit as the process to make the chemicals and dispose of waste may not align with everyone’s environmental priorities.  

💧 Water-Based Decaffeination

This chemical-free process is a favorite among specialty roasters and our method of choice for decaf coffees.

✅ How It Works:

1. Coffee beans are soaked in hot water, creating a Green Coffee Extract (GCE).

2. This solution is filtered through carbon filters that remove caffeine but retain flavor compounds.

3. The decaffeinated GCE is used to soak the next batch of beans.

4. Over several cycles, the caffeine is reduced to 0.1% or less.

This method preserves the flavor integrity of the beans and eliminates the need for chemical solvents. It’s used in both the Swiss Water Process (SWP) and the Mountain Water Process (MWP).

🔍 Why We’re Talking Decaf Now

So why all this talk of decaf?  We recently had the opportunity to explore alternatives to our popular Ethiopia SWP Decaf that we have carried for a couple of years. We sampled a variety of options from different regions by one of our green coffee importers, Royal New York, and when the grounds settled, and the spoons were put down, a clear favorite rose to the top. A well-balanced Mountain Water Process Brazil surprised even us on how tasty a Decaf could be! 

So, what better for this month's Coffee Recon than a head-to-head Brazil v. Brazil Decaf?   

☕ The Beans

Our main Recon bag is a delicious medium roasted Brazil sourced from our green coffee importer Royal New York. Brazil is a component in many of our popular blends and stands alone as a delicious, nutty and full-bodied cup with a touch of cocoa. 

Our sample Recon bag is also from Brazil, medium roasted and decaffeinated through the Mountain Water Process. It is medium bodied, with a dried fruit sweetness and mild nuttiness. Fig Newton anyone? We enjoy this addition to our lineup hot or iced and it holds up nicely in milk or milk-alternatives. 

🔥 Roasting Decaf: What Makes It Different?

Decaf, good decaf, is not as straightforward to roast as others. First, the unroasted beans are not typically green because the decaf process can turn them dark brown.

The different base color can make it difficult to visually determine roast progress. Also, decaffeination can change how the unroasted beans behave in the roaster as compared to their regular counterparts. That said, we did six test roasts on our Aillio Bullet to arrive at a coffee that we think brings the best out of this selection.  

You can see by the two roast profiles the different paths we took with each coffee to achieve the final results. Our regular Brazil is tried and true and roasts very consistently (almost boringly so). We typically drop Brazil between 417 and 419 degrees with about 3 min 15 sec of development.

The MWP Decaf Brazil behaved a little differently. It was an overall faster roast, but with a slightly longer development time. We also targeted a slightly lower drop temperature to preserve the flavor nuances that make it so special but with body we expect from a Brazil.  

While decaf may or may not be your speed, we think you will enjoy the delicious opportunity it adds to your coffee experience. And stay on the lookout for our Half-Caff and other lower-caffeine options in the future! Nightcap anyone?   

Happy Cupping! 

Adam