HOW IS COFFEE DECAFFEINATED? THE TRUTH ABOUT DECAF COFFEE
Decaf coffee is a great alternative for anyone looking to limit their caffeine intake. The best decaf beans compete with regular coffee in flavor and offer many of the same health benefits – without the risk of jitters or an energy crash.
In this article, I’ll explain the four main ways to decaffeinate coffee and discuss their relative merits. If you’ve been considering the switch to decaf but are nervous about the additional processing, read on for everything you need to know about decaf coffee.
How Coffee Is Decaffeinated: Four Methods
Decaffeinated coffee is any coffee with at least 97% of the caffeine removed. The first method of decaffeination is credited to Ludwig Roselius in 1905, a German coffee merchant who used benzene to draw caffeine from unroasted coffee beans (1). Fortunately, methods have since been refined considerably – and we now consider benzene a carcinogen.
Until recently, the main method of removing caffeine was chemical extraction. While modern coffee scientists use compounds much safer than benzene, the general public’s fear of “chemicals” is driving the popularity of newer chemical-free methods like CO2 and Swiss Water Process decaffeination.
The Indirect-Solvent Method (AKA The Methylene-Chloride Method)
Green coffee is soaked in hot water, which extracts much of the caffeine and other flavor compounds into the water. The beans are removed from the water, and methylene chloride is introduced to bind to the caffeine molecules. The methylene chloride-caffeine combination is then removed, and the beans are returned to the now-caffeine-free water to reabsorb the coffee flavor molecules.
Many coffee industry experts believe this is the best method for maintaining a coffee’s original flavor, but it leaves about 3% caffeine behind.
The Direct-Solvent Method (AKA The Ethyl-Acetate Method)
In this method, green coffee beans are steamed to open their pores for receiving the solvent. Then they are soaked in ethyl acetate to extract the caffeine. The solvent is evaporated, leaving behind decaffeinated coffee beans.
The ethyl-acetate method is faster than the others, making it more suitable for large-scale operations. Because ethyl acetate is a natural product derived from fruits and sugar cane, it is environmentally friendly and cost-effective in the many regions where both coffee and sugar cane are grown. The downside is that this method has the most impact on the coffee’s flavor; many aromatics evaporate along with the solvent.
Swiss Water Process (AKA Mountain Water Process)
The Swiss Water Process to decaffainte coffee entered the market in 1988 and has an organic certification. It doesn’t use chemicals and instead relies on osmosis and solubility to remove the caffeine from green coffee.
Swiss Water decaffeination is the most effective method, removing up to 99.9% of caffeine from the beans.
Like the indirect-solvent method, coffee beans are soaked in water to extract the caffeine and flavor molecules. But instead of using a chemical solvent, caffeine is removed by passing the water through an activated charcoal filter. The filter captures only caffeine molecules, leaving the flavor compounds in the water. The decaffeinated beans are resubmerged in the water to reabsorb the flavor chemicals.
CO2 Decaffeination
Carbon dioxide (CO2) is an effective but expensive method of coffee decaffeination, so it is generally only used by large-scale coffee roasters. It removes roughly 99% of the caffeine from coffee beans while leaving the flavor compounds largely intact.
Like the other methods, it starts by soaking the green beans in hot water to make them more accessible to the CO2. The softened beans are then placed in a highly pressurized tank pumped full of gaseous CO2. The carbon dioxide dissolves the caffeine, which can then be removed from the beans.
The CO2 with caffeine is moved to a separate tank where the caffeine can be removed and the CO2 recycled, rendering this method quite environmentally friendly.
Which is healthier, decaf or regular coffee?
In recent years, the safety of the indirect-solvent method of producing decaffeinated coffee has been called into question. Methylene chloride is a known carcinogen that has been banned in many commercial products (2).
As is the case with most chemicals, the dose makes the poison. The FDA regulates methylene-chloride decaffeination, mandating that “the residues of methylene chloride must not exceed 10 parts per million” in decaf roasted or instant coffee, and most producers are well below these limits (3).
Some special interest groups are still advocating for a ban, despite no scientific evidence linking the trace amounts of methylene chloride in decaf coffee to adverse health effects (4).
“There is no evidence that [methylene-chloride] decaf presents any risk. Indeed, the overwhelming weight of independent scientific evidence shows that drinking decaf, like all coffee, is associated with decreased risk of multiple cancers and with other significant health benefits.”
Of course, there is no harm in limiting your exposure to any amount of potentially toxic chemicals, and it is easy to find coffee decaffeinated by any of the other methods if you are concerned.
Health Benefits Of Decaf Coffee
Caffeinated coffee is associated with many health benefits, including an overall lower risk of mortality. While some of these are linked to its caffeine content, many stem from its high antioxidant content (5).
Decaffeinated coffee contains the same antioxidants as regular coffee and thus the same associated health benefits.
These include protection against type-2 diabetes, liver disease, cardiovascular disease, and certain cancers. Additionally, coffee without caffeine avoids the potential pitfalls of caffeinated coffee, such as anxiety, jitters, energy crashes, insomnia, and withdrawal headaches.
Why does decaf coffee not taste as good?
The coffee plant is incredibly complex, containing hundreds of unique flavor compounds (6). It is difficult to remove caffeine from coffee without also stripping away some of its flavorful aromatics.
That said, modern decaffeination methods are improving, and skilled roasters can generally compensate by adjusting the roast profile. So in my opinion, the best decaf coffee beans taste as good as a regular cup of coffee, just different.
Does decaffeinated coffee keep you awake?
Decaffeinated coffee is not entirely caffeine free. Indeed, recent research has found that almost all types of decaffeinated coffee contain caffeine in some quantity (7). A typical 12-ounce cup of decaf coffee has around 5 mg of caffeine.
So, if you are particularly sensitive to caffeine, you may still find it keeps you awake – especially if you drink it late in the day. Anecdotally, many people also report a placebo-like effect; the flavor and experience of drinking coffee gives them an energy boost, regardless of caffeine content.
There are many delicious coffee alternatives to consider if you want something entirely caffeine-free. Check out chicory coffee, mushroom coffee, date seed coffee, or herbal tea.
Final Thoughts
Decaf coffee is an excellent alternative for coffee drinkers who love the flavor of coffee but need to limit caffeine consumption. Modern roasters are producing decaf beans that brew rich and flavorful coffee, just like their caffeinated counterparts.
Like all food products, decaf coffee is regulated by the FDA and perfectly safe for consumption. It offers the same antioxidant content and many of the health benefits of regular coffee. However, if you’re concerned about trace chemicals, look for organic coffee companies or those advertising Swiss Water decaf.
FAQs
Decaf coffee made using the carbon dioxide or Swiss Water method is generally regarded as the most “natural.” But let’s not lose sight of the fact that water (hydrogen dioxide) is a chemical or that ethyl acetate is distilled from sugarcane. “Chemical” is not an inherently negative term.
Green coffee extract is actually a side product of the decaffeination process, made by soaking green coffee beans in water. It found fame as a health and weight loss supplement, largely due to its chlorogenic acid content, but there is little scientific basis for these claims. Advocates of the extract have faced countless lawsuits in recent years for false advertising (8).
Decaffeinated coffee does not cause acid reflux to the same extent as caffeinated coffee. Caffeine is known to relax the lower esophageal sphincter, which can trigger heartburn. However, a recent meta-analysis failed to find a link between coffee consumption and acid reflux (9).
References
- Merhi, Y. (2021, April 16). Unveiling the Secrets of Decaf. Retrieved from https://wolfsonian.org/blog/2021/13/
- OSHA. (n.d.). Methylene Chloride. Retrieved from https://www.osha.gov/methylene-chloride
- U.S. Food & Drug Administration. (2023, December 22). CFR – Code of Federal Regulations Title 21. Retrieved from https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?fr=173.255
- Rogers, K. (2024, April 5). Is decaf coffee safe to drink? Experts weigh in on claims by health advocacy groups. Retrieved from https://www.ctvnews.ca/health/is-decaf-coffee-safe-to-drink-experts-weigh-in-on-claims-by-health-advocacy-groups-1.6834007
- Poole R, Kennedy OJ, Roderick P, Fallowfield JA, Hayes PC, Parkes J. Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ. 2017 Nov 22;359:j5024. doi: 10.1136/bmj.j5024.
- Coffee Research. (n.d.). Coffee Chemistry: Coffee Aroma. Retrieved from https://www.coffeeresearch.org/science/aromamain.htm
- Barone JJ, Roberts HR. Caffeine consumption. Food Chem Toxicol. 1996 Jan;34(1):119-29. doi: 10.1016/0278-6915(95)00093-3.
- Chen, J. (2022, March 24). The Truth About Green Coffee Extract. Retrieved from https://sprudge.com/the-truth-about-green-coffee-extract-183824.html
- Kim J, Oh SW, Myung SK, Kwon H, Lee C, Yun JM, Lee HK; Korean Meta-analysis (KORMA) Study Group. Association between coffee intake and gastroesophageal reflux disease: a meta-analysis. Dis Esophagus. 2014 May-Jun;27(4):311-7. doi: 10.1111/dote.12099.
