To many people, decaf coffee is a mystery. Not only do they not know how much caffeine is found in decaffeinated coffee, but they also don’t know how decaf coffee is made. To clear all of this up, we’ve decided to explore this subject further. We’ve decided to not only talk about how decaffeinated coffee is made but also its history and caffeine content as well. So, if that sounds like something that you might be interested in learning, then feel free to follow along with us as we explore the mysterious world of decaffeination.
What Is Decaffeination?
Decaffeination is the process of removing caffeine from not only coffee beans but any product that may include caffeine—including cocoa beans or tea leaves. Depending on the process used, decaffeination can leave as little as 1% or as much as 20% of the product’s original amount of caffeine.
The History Of Decaffeination
Believe it or not, the reason why people started decaffeinating coffee beans was due to a request from the German poet and statesman Johann Wolfgang von Goethe. Although Goethe didn’t invent the process of removing caffeine from coffee beans, he did start Friedlieb Ferdinand Runge on the project. He did this after he had watched a presentation of Runge isolating and removing the poison found in the belladonna plant, and then using it to dilate a cat’s pupils. Goethe was so impressed with the result, he asked Runge to find out the ingredient in coffee beans that kept him awake at night. After a few months of work, Runge isolated the caffeine in coffee beans in 1920, and the rest is history as they say.
Although Runge managed to isolate caffeine in coffee beans so it could be identified, he didn’t attempt to pursue a commercial decaffeination process. That wouldn’t happen until a German merchant named Ludwig Roselius and a few of his co-workers invented the first commercially viable method of decaffeination in 1903. This process was called the Roselius Process and it processed steamed coffee beans with different bases and/or acids and then using benzene to remove the caffeine. Over the years, benzene was eventually replaced as a solvent for removing caffeine due to it being listed as a known carcinogen.
Nowadays, several different methods of decaffeination are used, and these include the Direct Method, the Indirect Method, the Supercritical CO2 Process, the Swiss Water Method, and probably the most popular method of all, the Swiss Water Process. Let’s take a look at these different decaffeination methods below, so we can get a better understanding of how these processes work.
The Different Ways Of Decaffeinating Coffee Beans
Okay, now we’re going to get to the heart of this guide: Finding out the different ways to decaffeinate coffee beans. Although we won’t go too deep into the technical details of each method, we can give all of our readers a basic overview of each process, so they can understand it better. If that sounds good to you, then let’s get started.
The Direct Method
Using this method, the manufacturer usually steams the green coffee beans for a preset period and then rinses them using either methylene chloride or ethyl acetate for up to 12-hours. When the solvent is removed, it takes the caffeine with it. The beans are then steamed again to ensure that any remaining solvents are thoroughly removed.
The Indirect Method
The second method of decaffeinating coffee beans is the Indirect Method. This method soaks the green coffee beans in near-boiling water for a few hours, and this removes the caffeine from the beans. Unfortunately, it also removes the essential oils and flavors from the beans, so additional steps are often required to reunite these flavors and oils with the beans.
After the water containing the caffeine, oils, and coffee flavors is separated into another tank, the water is then treated with methylene chloride to remove the caffeine. This prevents the solvent from coming into direct contact with the coffee beans. The water is then reunited with the beans where it can reabsorb the flavors and oils. The rest of the solvent is then vaporized during the roasting process.
The Supercritical CO2 Method
This method uses carbon dioxide under high temperature and pressure to remove caffeine from the coffee beans. The carbon dioxide enters the beans like a gas but dissolves the caffeine like a liquid. After the beans have been soaked in water for a while, which helps to expand cell structures and make caffeine removal easier, the coffee beans are then exposed to carbon dioxide for several hours. The carbon dioxide absorbs caffeine, liquefies, and then evaporates. As it does so, it takes the caffeine along with it.
The Swiss Water Method
The Swiss water method is another common way to decaffeinate coffee beans. Using the method, coffee beans are immersed in hot water, and that removes the caffeine and their flavor compounds from the beans. The beans are then discarded, and the green coffee extract is then passed through a carbon filter that removes the caffeine molecules. This extract is then used to wash and filter the next batch of beans. This allows the water extract to remove the caffeine without using chemical compounds, and without the beans losing their flavor compounds. This is why this method is most often used for decaffeinating organic green coffee beans.
The Final Word On Decaffeinated Coffee
Hopefully, all of the above information will prove useful to not only people who are interested in the science behind decaffeination but also for people who are looking to buy the best-decaffeinated coffee possible. We also hope that it will permit more people to purchase decaffeinated coffee products for their use. Although the decaf coffee of the past was pretty poor, the ones sold today are pretty tasty and are worth considering—especially if you have a sensitivity to caffeine. That’s probably why decaffeinated coffee accounts for approximately 12% of all worldwide coffee sales. If decaf coffee wasn’t good, more than 1 out of 10 people wouldn’t be enjoying it daily.