30 November 2015
Decaffeinated coffee is easy to find but decaffeinated Kona coffee is extremely rare. There are a couple reasons for this. First, most fans of Kona coffee don't drink decaf. That's understandable, I'm in that category myself. But there are some people who prefer decaf, or want a cup of coffee after dinner, or have been told by their doctor to switch to decaf due to hypertension. Whatever the reason, just because it's decaf doesn't mean it has to be bad coffee. Decaf drinkers should be able to enjoy good Kona coffee too.
The second reason decaf Kona is so rare is because the closest decaffeination plant is in Vancouver, Canada. Traveling from Hawaii to Vancouver and back is not cheap. It's only economical when shipping an entire container (thousands of pounds) of coffee. Not many Kona farmers can sell that much decaf coffee. To make matters worse, there are also some strict import laws. Any unroasted coffee entering the state of Hawaii must be fumigated. This applies even if the coffee was originally grown in Kona. Once coffee leaves the state it has to be fumigated before it can come back. This is to make sure that nobody accidentally imports any coffee pests or disease into Hawaii.
Fumigated coffee is considered safe for humans. Any chemicals that may be left behind on the coffee are destroyed in the roasting process. Still, fumigation sounds scary so many consumers avoid decaf coffee. Fumigation also increases the cost of the coffee. The cost of fumigation is in addition to the expense of traveling to and from Canada.
There is an alternative. It is possible, though certainly not easy, to decaffeinate coffee without needing a giant factory. It requires some fancy laboratory equipment and maybe some scary-sounding chemicals but it can be done. It's a complex process that is really easy to get wrong so when I heard of a local farmer that was decaffeinating coffee, I was skeptical.
Is it safe?I once overheard a barista telling a customer that decaffeinated coffee is poison. Of course, once confronted, this barista knew almost nothing about the process and was simply repeating her unfounded fear. The decaffeination process does involve chemicals with scary sounding names, such as dihydrogen monoxide, but the FDA says it's safe. One of the scariest chemicals, methyl chloride, is listed as a possible carcinogen at higher levels. The FDA considers it safe in concentrations below 10 parts per million. Decaf coffee contains less than 1 part per million. For comparison, the acute inhalation toxicity level (toxic after inhaled continuously for eight hours) in lab rats is way up at 2000 parts per million.
Still, if methyl chloride is potentially dangerous, why risk it at all? Well, quite simply, because it works great. Other solvents remove sugars, proteins and other organic materials that can destroy the coffee but methyl chloride binds with the alkaloids in caffeine while leaving everything else alone. This means better tasting coffee. Safe + better flavor = win!
Not so fast. Fear > flavor. Many consumers, and some baristas, don't care what the FDA says is safe, they still don't want any "chemicals" in their food. This is where the power of marketing wins. If you can call dihydrogen monoxide something less scary, like water, then people will buy it. So the most popular decaffeination method is the Swiss Water® process. There is only one decaffeination plant in the world that uses the Swiss Water process and that plant is in Vancouver, Canada.
Swiss Water Decaf is great, and I'm not just saying that because I've worked with them before. Having a fancy factory let's them control the entire process in ways that a smaller producer simply can't. To keep things in perspective, their minimum batch size is 7000 pounds. By comparison, I think 100 pounds is a lot of decaf.
Do not dispair, there is yet another solution. This is called the CO2 process or, if you're in marketing, the Sparkling Water method. Basically, the solvent used is supercritical carbon dioxide. That's great because carbon dioxide doesn't sound so scary. The term supercritical means the carbon dioxide is pressurized to the point that it moves through the coffee beans like a gas and dissolves the caffeine like a liquid. When the pressure is released, the CO2 goes back to being a gas and the caffeine falls out.
Don't be mislead, while the CO2 process sounds safe and easy, there are some caveats. Here's a video of a home-built attempt at extracting caffeine with supercritical CO2.
Caveat #1: Taking a metal pipe and filling it with a huge amount of pressure sure is a good way to make a bomb. This is probably not something you should build in your basement.
Caveat #2: The process shown in the video is "successful" if you want a pile of caffeine but very unsuccessful if you want drinkable decaf coffee. In the video, once some caffeine is extracted then the beans are ignored. That's backwards! The general method is correct but producing good decaf coffee would require a lot more attention to details and some expensive food-grade equipment.
Caveat #3: Pure caffeine is dangerous! If you think methyl chloride sounds scary, watch out for pure caffeine. A single teaspoon is equivalent to 25 cups of coffee. Even if it doesn't kill you, it will certainly ruin your day. After all, the reason the plant produces caffeine in the first place is because it's a great pesticide. Think of it like table salt, it's safe and pleasant in small amounts but in large concentrations it will seriously mess up your body chemistry.
Did we answer the question of whether or not decaffeinated coffee is safe? I think we can confidently say that for the consumer, yes, decaffeinated coffee is safe. For the person doing the decaffeinating though, he or she might want to wear safety goggles.
Is it really caffeine free?The FDA requires decaffeinated coffee to have at least 97% of the caffeine removed. 97% is most but not all. A cup of decaf coffee still contains about 10mg of caffeine. By comparison, a soda contains 34mg (source: the back of the can I'm holding) and a normal cup of coffee contains 100mg - 300mg of caffeine.
It's difficult to know how much caffeine is in your cup of coffee because not only does cup size vary wildly, so does the amount of caffeine in different types of coffee. Robusta coffee naturally contains more caffeine than Arabica. I suspect the caffeine level varies from tree to tree too, though I doubt that has ever been measured. There's even a type of coffee that is naturally caffeine free. Nobody drinks it because it tastes like dirt.
ResultsThe local decaf producer has lab results showing that the resulting coffee is indeed considered decaffeinated. That's good. Now, assuming we leave the mad-scientist stuff to someone else, all that's left for us to decide is whether or not the decaffeinated coffee is drinkable. That's why I decided to let other Kona coffee farmers try it first.
The results are in and it seems to be a success. It's difficult for me to tell because I'm not exactly a connoisseur of decaffeinated coffee. The unroasted green beans are very obviously different but that visual difference is less obvious once the beans are roasted. Once the coffee is brewed and in the cup, it's difficult to tell a difference at all, it looks and smells just like normal caffeinated coffee. There is a taste difference but it's more subtle than I expected. With a little practice I could learn to identify the difference but if you didn't tell me what was in the cup, I might not notice.
I always hear people complain about how horrible decaf coffee is but when I brewed it and tried a cup, I was pleasantly surprised. It's not my best coffee but I didn't expect it to be. It certainly good enough that now I can enjoy a cup of coffee after dinner and still sleep fine.
If you're a long time decaf drinker, I'd be interested to hear your feedback. I'm not particularly interested in feedback from non-decaf drinkers because we're all biased. This isn't about decaf versus regular, this is about finding a decent cup of decaf. So let me know what you think and if there's enough demand, maybe we'll make more.