The Truth About Decaf Coffee
How is it made? And how much caffeine is really in it?
Science is strange. Sometimes it can say that caffeine is good and even safe to drink for those with heart failure, and other times it flat out says caffeine is bad even for the healthiest of individuals. Either way, decaf coffee is a good choice for those of us who want to enjoy our favorite drink— minus the caffeine.
Separating coffee from caffeine sounds a little counterproductive and flat-out pointless at first. After all, caffeine is named after coffee, so their relationship is very important.
Caffeine contributes to bitterness and, by itself, can cause irritation of the stomach, which is why the removal of caffeine in coffee can lead to partial loss of its original flavor if not done carefully.
In terms of being “decaffeinated”: it is not, in the widest sense of the word. Decaffeination can only remove 97% of the total caffeine content at best. This means that a cup of decaf will still contain some caffeine, although the amount is practically meaningless— about 7 mg per cup, while a regular cup contains 140 mg or more per cup.
So let’s answer the big question: how are coffee beans decaffeinated?
There are two methods most commonly used for decaffeinating coffee beans:
#1 Swiss water method
The swiss water method came up as a solution for old methods invented more than a century ago which used solvents that are very bad for our health. Instead, the swiss water method (invented in 1933) uses only water.
Green coffee is soaked in hot water to extract the caffeine, yet it is then passed through an activated charcoal filter. This filter traps in it most -if not all- of the caffeine molecules. Those beans are then discarded, and it’s the caffeine-free green coffee extract that is used.
Now, the good coffee is soaked in this water, and a magical thing happens: caffeine is attracted towards this water, and so it migrates from the beans and into this water.
This process can be repeated ad nauseam, but it varies depending on the seller’s needs. Caffeine content will, however, be higher the less times the process is repeated and vice versa.
#2 Supercritical CO2
Carbon dioxide, usually a gas, can turn liquid when you apply the right amount of pressure and heat. This is anywhere from 100 to 1000 bars of pressure— an espresso is extracted using 15 bars of pressure, just so you get an idea. Temperature must be above 31°C or 87.8 °F for it to become supercritical.
Carbon dioxide used like this has dominated the market for solvents because compared to most others used before, this solvent is completely harmless to the body in small quantities. It is not toxic and -most important of all- it is cheap. Also, it’s rather good for the environment and you don’t need to resort to invasive practices (like deforestation) to get carbon dioxide.
In a similar manner to the first method of decaffeination, supercritical carbon dioxide is run through coffee beans enough times so that the caffeine is extracted. Unlike swiss water, this method is much less invasive and sometimes credited to achieve a better flavor in the cup than other methods.
In the end, one thing is sure: decaf coffee is not the same as any other coffee. Whether you use one process or the other, the truth is that the science is not clear on what else we’re removing from the coffee beans along with the caffeine. Or what could be added to them, even. What is clear is that caffeine content goes down: that’s more than enough for now.
While not the same in flavor or taste, decaf coffee can still be delicious if properly roasted by experienced people on this particular subject.