How They Decaffeinate Coffee

When it comes to drinking coffee, it seems like it's a love/hate relationship. Ok, maybe hate is a little strong, but most of us either like or don't like coffee. Amongst the likes, there is also another relationship: regular vs. decaf. Not to mention that we are constantly bombarded with how coffee is good for you one minute and not the next! Then there are some of us that just can't do caffeine like we used to! So today we talk about the process of decaffeinating coffee and why we chose the Sugar Cane method.

There are two important questions we started with as a coffee roaster. How do you find a good decaf coffee bean to roast and what decaf process do you prefer?

There are a few things to remember. All decaffeinated coffee starts at the same point and share some common things- the first, green coffee beans. Here is the process at a glance, ending with the four ways or solvents used to get to the end result:

  • Start with green (unroasted) coffee beans.
  • All methods use water, since caffeine is water soluble.
  • Challenge of taking out the caffeine while keeping the approximately 1,000 chemicals intact that provide coffee with its beautiful elixir.
  • All processes use a solvent or agent in the process since water is not "selective" in what it removes. These four solvents used are all organic (carbon-containing) substances that help achieve the end result. They are methylene chloride (CH2Cl2), activated charcoal (C), Carbon Dioxide (CO2), and ethyl acetate (C4H8O2). 

Since we are new to roasting, this opened up a world of questions on which decaf process would be best. There are four commonly used decaffeination processes as listed above. Since caffeine is water soluble, the various methods used contain soaking the beans in water and a solvent to extract the caffeine and preserve the natural flavor of the coffee as best as possible. So which one is best to use? Much like a painting, the beauty is in the tongue of the taster! We try our best to discover what that is and wether it's going to serve our clients the best overall.

We decided to go with Sugar Cane method or ethyl acetate method. Two reasons for this: first sugarcane is abundant and growing in Columbia and using a Columbian bean this has an environmental and socially responsible benefit as well. The second is a lower disruption of the cell structure. It doesn't require heat or pressure like some of the other methods, which are very likely to disrupt the end flavor result. It is a fermented molasses that doesn't disrupt the beans cellular structure and even enhances the sweetness of the end result. The ethanol, which is also found in wine, beer, fruit and vegetables, is used with the solvent to achieve this process by dissolving the caffeine and leaving more of the things that you want in the taste of your coffee without the caffeine.

The solvent-laced water is basically reused again and again until it is filled/packed with coffee the coffees flavor and compounds – as identical to the beans as possible, except for the caffeine and solvent. By this stage in the process the beans lose very little flavor because they’re essentially soaked in a concentrated coffee essence. Keeping that beautiful elixir so many of us love!

I have discovered that just like tasting wine, coffee taste is perceived by each individual in their own way. Sure we can provide a taste profile, but when that individual sits down to enjoy their cup, they may not pick up the same flavors as I do. This is also determined by the roast. Let's take our sense of smell for instance. I think my nose and smell is pretty acute, I can smell a fire or a dirty diaper long before everyone else. That is not the case for all. Our sense of smell is directly related to our taste. So if you don't pick up the same notes that I do, does that make it good or bad? (The answer to that question would leave us here forever!)

Lastly, why we only roast the decaf to a medium roast. When it comes to decaf coffee, the beans do not react the same to heat as other green beans. This means that reaching the highest and best flavor profile for this particular bean is roasting it to a full city or medium roast. The fermented molasses from the sugar cane, the Sugar Cane Process creates beans with a pleasant, clean, and sweet flavor when roasted to a full city/medium roast. We have tried light and dark roast for our Columbian decaf, and it didn't serve to compliment the beans like it does when at a full city roast.

Remember that there is not such thing as 100% decaffeinated coffee. Coffee only needs to be 97% caffeine free to be considered decaf. Decaf coffee is also a good to have on hand item for the next time you decide to host a gathering! Those of us who drink regular, will also most likely drink decaf if given the option. I think all will be pleasantly surprised.

I hope you enjoyed learning about the Sugar Cane decaf process and why Oak Glen Coffee chose to carry the Columbian Sugar Cane decaf!


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