Get Thee Behind Me, Sanka!
Some of us can't imagine drinking decaffeinated coffee. The mild (or not-so-mild) buzz that comes with your cup o' joe is, after all, one of the many perks of coffee drinking. However, for some people -- especially those with high blood pressure, or who might be taking certain medications, or who may have a caffeine sensitivity -- decaf does prove to be a better option. How is coffee decaffeinated? Let's find out.
While there are a few decaffeination processes, they all have some things in common. First, each process is done prior to roasting. Second, no process removes all of the bean's caffeine content.* Finally, given the complex nature of coffee -- hundreds of organic compounds that, when roasted, undergo chemical changes to become a thousand compounds or more -- decaffeination alters the taste of coffee markedly, since no decaffeination process effects only the caffeine.
The original decaffeination process was patented in 1906, and thankfully is no longer with us (it involved the use of benzene**). Many processes currently in use work on similar principles: steam or boil the green coffee, apply a filter or solvent to remove the caffeine (an activated charcoal filter in the Swiss Water Process, chemicals such as dichloromethane and ethyl acetate in most industrial processes), rinse the beans, and re-flavor them.
Folgers Decaffeinated Coffee
In the less-common "direct method", the beans are steamed and then heavily dosed with solvent to remove the caffeine, after which point they're steamed for a long period of time to extract the solvent. The more common "indirect method" bathes the beans in a hot water and solvent mixture, filters out the caffeine, and then bathes the beans in the resulting stew of water and coffee extract so that some of them are reabsorbed. The leftover caffeine, meantime, is sold to soft drink companies and drug manufacturers.
And that brings us to why decaf typically tastes so flat. Decaffeination isn't just removing caffeine; it's removing several other chemical compounds that the roaster then hopes will be soaked back in during the final steps of the decaffeination process. But if you do the math, the less organic compounds you start with (especially when you're dealing with something on the order of complexity as the chemical reactions in coffee roasting), you're going to end up with far fewer at the end of the roast process as well. The flavor? Gone. The health benefits of coffee? There haven't been many studies on decaf, but we'd guess that they'd be greatly diminished.
Caffeine is just one of many benefits (besides taste and a host of healthful compounds) delivered by a cup of coffee. If you can't have the caffeine because your health, diet, sleep schedule, or religion prohibits it, decaf can be a viable alternative. Just be sure to find a decaffeination process that works for you, and that does a better job of preserving the taste of your coffee.
*Check the bean content; caffeine content will be lower on 100% Arabica coffee than on blends containing Robusta (e.g. supermarket stalwarts such as Folger's and Maxwell House), since Robusta beans have a higher caffeine concentration. (Source
**Speaking of chemical decaffeination: every so often, you may come across a rumor -- or someone emphatically stating as fact -- that one brand or another of decaf uses formaldehyde to decaffeinate its coffee. Those rumors once had some truth to them. However, the FDA outlawed the use of formaldehyde in decaffeination in 1985, so as long as you're not cracking open a thirty-year-old jar of instant Sanka, you don't have to worry about being slowly embalmed by your decaf habit.
Find out more about decaffeination thanks to the folks at Scientific American: How is caffeine removed to produce decaffeinated coffee?