Decaffeination Conundrum: Which Method Removes Caffeine while Preserving Health and Flavor?

You love coffee, the aromas and flavors of a magnificent cup beckon you at all hours of the day, but alas your body can’t tolerate the caffeine. 

Some folks seem to be able to drink cup after cup of caffeinated java with little to no physical effects, while others, for one reason or another, are sensitive to the stimulating effects of even one cup of joe. 

If you find yourself in the latter group, needing or preferring decaf coffee selections, you may have pondered, “just how on earth is decaf coffee made?” 

Well, today we’re going on a journey to answer that exact question.

There are actually four methods used to decaffeinate coffee. Here we’ll explore each method and see which one ranks supreme in the process, resulting flavor, and health! 

But First, Coffee Cherries

When you prepare to brew your coffee, the product in your hands, whole beans or pre-ground, is very different from what is harvested from the coffee plant itself. 

Coffee plants produce beautiful, bright red coffee cherries, often referred to as fruit. 

And, inside the coffee cherry is a seed or the raw form of the coffee bean. 

While each part of the coffee plant contains caffeine, it is this seed, or raw coffee bean that contains the highest amount of the stimulant. 

Within the cherry, covering the bean is a sugary, sometimes slimy coating called mucilage. This, along with the outer layers of the coffee cherry are removed as the fruit is washed, dried, and processed. 

The result is a light green colored bean which will soon be ready for roasting; however, if the bean is destined for decaffeination, this is the point in the coffee producing process where the magic happens. 

But, why remove the caffeine prior to roasting? 

First, the raw green coffee bean contains a greater amount of caffeine than a roasted bean, so decaffeinating at this point allows for the greatest amount of the stimulant to be extracted. 

And, since the average 8 ounce cup of coffee contains approximately 95 mg of caffeine, removing the most caffeine possible is obviously a big deal! 

Second, decaffeinating while the beans are green and raw best protects the flavor of the coffee. 

A side note? It is actually said that roasting and then decaffeinating would produce a flavor resembling straw! 

Hmmm, I think we’ll just take the experts’ word on that one instead of sampling a straw-flavored cup of joe.

So, let’s just move right along to the ways in which caffeine is removed from coffee. 

Removing The Caffeine From Green Coffee Beans

There are four common methods used to decaffeinate coffee - direct solvent, indirect solvent, the supercritical carbon dioxide process, and the Swiss water process. 

The two methods of decaffeination that require the use of chemical solvents are the direct and indirect solvent methods. We’ll start there… 

Direct Solvent Method

The direct solvent method used for removing caffeine from coffee is said to have originated in Germany in the early 1900’s when a coffee merchant by the name of Ludwig Roselius received a shipment of coffee that had been soaked in sea water.

Roselius opted for conducting a bit of a science experiment, testing and processing the beans, instead of simply discarding them.  And, what he discovered was that the beans had been stripped of their caffeine content, even if they did taste a bit salty from the seawater. 

Soon, Ludwig found that benzene, a common chemical used in paint strippers, could bring about the same effect, removing caffeine from the green coffee beans. 

Benzene, now a known carcinogen, is no longer used in the decaffeination process. Instead, the direct solvent method incorporates the use of ethyl acetate and methylene chloride to remove caffeine from coffee. 

In this method, first the beans are steamed, opening their pores. Then the beans are soaked in the methylene chloride and ethyl acetate which strips them of caffeine. 

After being soaked in these solvents, the beans are steamed, dried, and roasted to remove any solvent residue. 

Aside from the use of chemicals in this method of decaffeination, soaking the beans in these solvents can also remove other compounds in the coffee, resulting in compromised flavor. 

*As ethyl acetate can be found in some fruits and vegetables, when this solvent is used in the decaffeination process, the end product can often be termed “naturally decaffeinated.” If you are looking for coffee that is decaffeinated without the use of a chemical solvent, it is important to be aware of this terminology. 

Indirect Solvent Method

Also known as the indirect contact solvent method of decaffeination, this process uses the same chemical solvents as the direct method, methylene chloride and ethyl acetate, but in an indirect manner. 

First the raw, green coffee beans are soaked or steamed in near boiling water for several hours, allowing the caffeine to be gradually drawn out of the coffee. 

Throughout this process, the caffeine, as well as the flavor compounds and oils of the coffee are removed. 

Then, the coffee beans are removed from the solution, and the chemical solvents listed above are added to the remaining liquid so they can absorb the caffeine. 

The entire mixture is then heated, causing the caffeine to evaporate along with the chemical solvents. 

At this point the coffee beans are reintroduced to the decaffeinated solution to reabsorb the flavor compounds and oils lost in the initial soaking. 

In this method, the coffee beans are said to never specifically come into contact with the caffeine stripping solvents. 

However, like the direct solvent method, the flavor of the coffee after this process is often described as milder than typical caffeinated coffee. 

Supercritical Carbon Dioxide Process

This method of decaffeination differs from the first two methods discussed as this process does not incorporate the use of chemical solvents, instead incorporating the use of carbon dioxide. 

To remove the caffeine from green coffee beans in this method, the beans are pre moistened, then spread out onto surfaces where high-pressure vessels circulate carbon dioxide throughout them. 

The unique name of supercritical comes into play here as the carbon dioxide takes on useful solvent-like properties, with a density similar to liquid, and a viscosity and diffusivity similar to that of a gas. 

The carbon dioxide works to strip the caffeine from the beans without removing the oils and flavor compounds. 

At this point, the carbon dioxide, now essentially laced with caffeine, can exit the vessel through either activated charcoal filters or water, both of which absorb the extracted caffeine from the carbon dioxide. 

While this method does not use chemical solvents, it does come with a hefty price tag. 

And unfortunately, though it is considered environmentally friendly, this process can be hazardous to workers as carbon dioxide, in compressed form, can rapidly expand; therefore, in the event of an accidental release, oxygen becomes displaced and workers tragically asphyxiate. 

Swiss Water Process

The last method of decaffeination we’d like to discuss is the method that we use here at Lifeboost - the Swiss water process. 

In a moment we’ll discuss why we have chosen this method, but first, let’s detail the process. 

This method of decaffeination was first discovered in 1930’s Switzerland and is considered the cleanest and healthiest process as water is the main (only) solvent. 

Here, green coffee beans are soaked in scalding hot water to separate the caffeine from the beans.

Next, the coffee beans are set aside, and the water is run through a charcoal filter, where the caffeine molecules become trapped in the porous charcoal. 

At this point in the process, the caffeine is removed from the water solution and only a flavorless (caffeine-free) extract remains. 

Now for the fun part…a new batch of green coffee beans (fully caffeinated) is soaked in this caffeine-free green coffee extract. Here, as the caffeinated coffee beans and the caffeine-free extract seek equilibrium, the caffeine from beans migrates to the liquid, rendering the coffee beans caffeine-less, without the use of a chemical solvent. 

The beans retain their flavor compounds and oils, and the caffeine is removed.

This extract is then filtered through the porous charcoal again, removing the caffeine and being set aside for use on the next batch of green coffee beans.

At Lifeboost, we incorporate the use of the Swiss water process for decaffeination as this method omits the use of any chemical solvent. 

The Swiss water method is natural, poses no threat to the environment, and even removes more caffeine than the other methods. 

That’s right! Most decaffeinated coffees aren’t completely caffeine free! 

The Swiss water method of decaffeination removes 99.9% of caffeine, while the other methods remove only 96-97%. 

The process incorporated in the Swiss water method also preserves the antioxidants found in coffee, part of what makes this beloved bean so beneficial to your health. 

At Lifeboost, we care about the environment and your health, which is why our coffee cherries are grown organically, at high elevations, using sustainable farming practices. 

Then, with healthy, delicious, quality coffee as one of our top priorities, we only use the Swiss water process when we decaffeinate our single origin, specialty Arabica coffee beans prior to roasting them to perfection! 

Check out Lifeboost Coffee Highlander Grogg Decaf. 

References:

https://sipcoffeehouse.com/coffee-cherry/

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https://espressocoffeeguide.com/decaffeinated-coffee/indirect-contact-method-of-decaffeination/

https://www.livescience.com/65278-how-decaf-coffee-is-made.html

https://www.todayifoundout.com/index.php/2011/04/how-decaffeinated-coffee-is-made/

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