How Is Coffee Decaffeinated? The Real Buzz Behind the Decaffeination Process
Caffeine is a naturally occurring substance found in coffee, tea, and cacao. Millions of people worldwide depend on this stimulant for a morning energy boost. And while caffeine does not adversely affect the vast majority of people, for some it can cause digestive problems, anxiety, and tremors, and disrupt sleeping patterns.
Decaffeination was invented to remove the caffeine from coffee and tea, allowing those who cannot tolerate it to still enjoy a nice, hot beverage.
The biggest challenge to decaffeination is making sure that the end product, such as coffee, retains its flavor and taste qualities that make it desirable.
Because coffee beans contain thousands of chemicals comprising their complicated flavors and aromas, extracting just one of these components – caffeine – while preserving flavor can prove to be a difficult task.
Caffeine, like many other chemicals in a coffee bean, is water soluble. Additionally, the caffeine molecule has great affinity for several chemical compounds – or solvents – also used for this purpose. Various decaffeination methods take advantage of this particular characteristic to effectively remove as much caffeine as possible.
So How is Coffee Decaffeinated?
The decaffeination process goes something like this:
- Green – or unroasted – coffee beans are placed in a solution to remove the caffeine from the beans. (Unfortunately, many other compounds are removed at the same time.)
- The caffeine is removed from the solution, leaving all other compounds intact.
- The compounds are returned to the coffee beans.
Sounds simple, doesn’t it? Well, it’s easier said than done.
While the process is somewhat complicated, it can be accomplished in several ways that are both safe and preserve the coffee beans’ flavors.
Two main methodologies of decaffeination exist: Solvent-based and non-solvent based. Each has its own variations, as well.
Solvent Based Method
Indirect Contact Process
Using this process, coffee beans are soaked in hot water to remove the caffeine in them. As mentioned, many other flavoring compounds are also extracted. The solution is treated with a solvent (either methylene chloride or ethyl acetate) resulting in a solution saturated with all of the beans’ compounds except caffeine. At this point, the green caffeine-free beans are reintroduced to the solution until they absorb their compounds back and regain their flavor.
Direct Contact Process
Steaming green coffee beans allows them to more readily release caffeine into the solvent used. After steaming, beans are rinsed with the solvents repeatedly until the caffeine contents reach desired levels (usually less than 3%). Using this method, there is no need to put flavors back into the bean, as the solvents are targeted to extract caffeine and not the other compounds.
Non-Solvent Based Method
Water Based (Swiss Water Process)
Similar to the solvent-based indirect contact method, this process begins with green coffee beans being soaked in hot water. The caffeine-charged solution is then filtered through a specially treated set of carbon filtration units designed to extract caffeine from the solution, leaving the remaining flavoring compounds intact.
Here, the process changes somewhat. The initial batch of green coffee beans is subsequently discarded, and a new batch of green beans (still caffeinated) is introduced to the flavor-charged, caffeine-free-solution. Since the solution is already saturated with the beans’ compounds, excluding caffeine, it cannot extract any more flavoring compounds from the beans. It can only extract caffeine.
Carbon Dioxide Process
In this method, green coffee beans are steamed and placed in a pressurized vessel, where they are rinsed with liquid CO2. Because caffeine is soluble in CO2, but the remaining compounds are not, the flavoring compounds remain in the beans. The caffeine is then removed from the CO2, which is rerouted to the vessel where it continues removing caffeine from the beans for 8-10 hours, achieving the desired caffeine levels.
The result? Caffeine-free coffee.
While the described methods achieve similar results, they incur additional costs as a result of the unique processes used, as well as shipping. Decaffeination is only done in a few places in the world such as Canada, Germany, and Colombia.
Over the years, many individuals have expressed concerns regarding the effects of chemicals used in food processing. However, the chemicals used in the decaffeination process have been deemed safe by the FDA after extensive testing and long-term use by the food industry.
Consider this: methylene chloride evaporates at just over 100 degrees Fahrenheit, leaving no residue. Green coffee beans are roasted at 400 degrees and are later brewed in water that reaches 200 degrees, virtually eliminating any solvent that may remain in the beans after the decaffeination process. Ethyl gas is naturally produced by most ripening fruit, including bananas, mangos, and avocados, which is why these fruits will ripen faster if left in a bag, and CO2 is a gas naturally present in our atmosphere and not a health threat in this use.
Today’s decaffeination processes provide a safe path toward an exceptional cup of coffee. For those individuals who suffer from insomnia, irritability, increased blood pressure, and more following excessive caffeine consumption – making the switch to decaf may be the best of all options.
Orinoco Coffee & Tea offers a number of decaffeinated coffees, from our signature house blend to flavored favorites such as our English Toffee or Cinnamon French Toast. Try a bag today.