This article is Part II of Foodie Abroad’s look at decaf. For Part I see here.
In January, I caught a terrible cold that left me wallowing in bed for several days. During this time, I did not drink any coffee. Caffeine addiction defeated, I make a decision not to go back. This time for real, but the coffee habit remains and I have opted for decaf.
People, especially coffee drinkers, tend to have strong feelings towards decaf. “What’s the point?” they ask. The point is that I drink coffee not as a necessity but rather because it is delicious. “Decaf always tastes bad” they declare. Well, fear not decafaphobes, there are some decaf beans on the market that are smooth and delectable. But given the high level of processing necessary to get rid of the caffeine, taste and quality are often compromised. There is research underway into the development of lower caffeine beans and the promotion of a low-caffeine strain. Also, I should note that a US National Institutes of Health study found that drinking decaf may increase cholesterol.
This is an article for decafaphobes and caffeine lovers alike, it is a brief study of the bean and the brew.
So what exactly is decaf and how do they de-caffeinate beans?
First, it’s decaf, not uncaf, which means that there still is some caffeine in the beans. The International Organization for Standardization’s standard states that to qualify as decaf, beans must be 97% caffeine free. In Europe, the standard is 99.9% caffeine free.
There are several processes used to achieve a decaf bean and some are better than others. Experts suggest that there should be no difference in taste between caffeinated and decaffeinated coffee, so long as the flavour compounds are not affected by the process. Your own aversion to decaf, or conviction that decaf tastes different, could have more to do with the way it was prepared and the age of the beans. Given that there is lesser demand for decaf, the brews tend to sit longer, the coffee tends to go stale faster, things that negatively impact the taste of your beverage.
Swiss Water Process
In this process green coffee beans are soaked in hot water. This process removes the caffeine but also many of the compounds responsible for flavour. The process results in two things: beans with no caffeine and no flavour, and water full of flavour components but no caffeine. The first batch of beans are discarded but the flavoured water is used to removed the caffeine from a second batch of beans. In this second stage, the caffeine dissolves, but the flavours do not because of the chemical component of the flavoured water. This second round of beans, retaining its flavor, is now decaffeinated and ready to be dried and roasted.
CO2 Process
Here, highly compressed CO2 extracts the caffeine from green coffee beans and then the caffeine is removed by way of a carbon filtration process.
Sparkling Water Process
This process resembles the CO2 method, but instead of removing the caffeine with carbon filters, the caffeine is washed from the CO2 with sparkling water in a secondary tank.
Direct Chemical Process
In this process, green coffee beans are soaked and then rinsed with methylene chloride (DCM), The DCM soaks through the bean, drawing out the caffeine. The FDA contends DMC levels found in decaf are acceptable for human consumption, but they have banned DCM for use in cosmetics and hair sprays. Yummy. Ethyl acetate is also used in direct chemical processes. I might steer away from these…
Indirect Chemical Process
In this process, green beans are soaked in hot water to dissolve the caffeine. Next, the water is separated and the beans are treated with an ethyl acetate solvent that removes the caffeine. Then, flavour compounds in the water are returned to beans. The beans are once again rinsed to remove final traces of ethyl acetate.
As I mentioned above, decaf beans can be every bit as delicious as caffeinated beans. The work is in the roasting and the brewing. So next time you are about to have a cup of coffee, think about having a decaf for it’s flavour.
