What is Decaf Coffee?
Quite simply, decaf coffee is coffee that has had most of the natural caffeine removed from green coffee beans before they are roasted. The decaffeination process happens after the normal sorting, washing, and drying processes of coffee are finished. Like all coffee, the quality of decaf coffee is determined by many factors, including location, environmental factors, method of processing, quality control in picking and processing, and quality/style of roasting. Generally speaking, decaf coffees have a milder, less bold flavor, than regular coffees.
Does Decaf Coffee Have Any Caffeine?
The process of decaffeination removes most of the caffeine from the green coffee beans. However, there is always a small of amount of caffeine that remains. Some studies have shown that decaf coffees can still contain enough caffeine that it could still affect people who are sensitive, if they drink enough of it (see sources below). Caffeine levels depend on roast level and brewing method so the amount of caffeine in decaf coffee can vary fairly significantly. Estimates suggest that it could take anywhere from 5-10 cups of decaf to equal the amount of caffeine in a regular cup of coffee.
How Is Caffeine Removed from Decaf Coffee?
There are three primary methods used for the decaffeination process. All three methods either water soak or steam the green coffee beans to make them swell and get their “pores” to open up. This opening up allows the caffeine then to be removed using one of these methods:
This is one of the most widely used methods of decaffeinating coffee. Over the years a few different types of solvents have been used for this process. Unfortunately, quite a few of these solvents were toxic with negative health results. Because of this they are no longer in use. The two common solvents used today are methylene chloride and ethyl acetate. The FDA has approved both of these solvents for use, but many people still maintain a legitimate concern of negative effects from these solvents.
Many companies that use ethyl acetate still misleadingly label their coffee as “naturally-decaffeinated” because ethyl acetate is a solvent that occurs in nature. However, the methyl acetate that is used in decaffeination is a synthetic variety of this solvent rather than the natural form. Don’t be fooled the next time you see a “naturally-decaffeinated” label.
Here at Javataza we have stayed away from decaf beans that used the solvent-based method in an effort to be quality, environmentally, and health conscious.
Carbon Dioxide Process
This is the most recent method of decaffeination. It utilizes CO2 in place of chemical solvents and is a bit more targeted in what it releases from the caffeine. In this method, the green coffee beans are placed into a sealed stainless-steel extraction vessel that is injected with liquid CO2 at a high pressure. This pressure extracts the caffeine and the C02 along with the caffeine is transferred to another container.
This process holds promise and is not as invasive as the solvent process, but it is expensive and takes significant setup. Because of this, it is generally used only for large scale, commercial grade coffee setups, making so that most coffees that use this method are lower quality coffees that are not grown with sustainable practices.
Swiss Water® Process
This is a chemical-free decaffeination process that was developed in Switzerland in the 1930s. It became a more commercially used process then in the 1980s and the Swiss Water Company in Canada remains the flagship of this method today.
The swiss water process is a fascinating process that uses hot water to extract the caffeine and the flavor from an original coffee bean batch. This batch of flavorless beans is discarded while the water then is run through an activated charcoal filter that is designed to only capture the caffeine particles and allows all the oils and flavor components of the coffee to pass through. This water then is used to flow back into a new batch of green coffee beans. However, since the water is already flavored, the flavors in the fresh batch of beans is unable to dissolve, leaving only the caffeine to be removed. This is an environmentally-friendly and healthy way to remove caffeine and still maintain a good quality coffee product.
Here is a short video showing more about the Swiss Water Process.