Decaffeination Processes

Decaff Processess for Coffee

Sometimes a food can be unacceptable if one process is used but fine if another is used. Decaffeinated Coffee is one example. The chemicals used in some decaffeination processes raise health and environmental concerns.

There are four major commercial processes used to remove caffeine from coffee.

  • Conventional decaffeination uses the chemical Methylene Chloride
  • "Natural" decaffeination uses the chemical Ethyl Acetate.
  • Water decaffeination uses water
  • Carbon Dioxide decaffeination..uses, you guessed it, carbon dioxide.

Each of these methods does a good job of removing the caffeine from coffee (to sell a coffee as decaffeinated it must be at least 97% caffeine free). However, there are significant differences in the taste of the decaffeinated product, in the residual chemicals remaining in the beans, and in the effect on the environment.

Natural Decaffeination - uses Methylene Chloride a solvent. Although Methylene Chloride levels in the coffee bean are reduced to residual levels that are "legally safe" (the FDA has set a maximum allowable level of 10 parts per million), health conscious consumers, skeptical of government infallibility, consider these residues unacceptable.

Ethyl Acetate Decaffeination - Coffee decaffeinated using this process is frequently referred to as "Natural Decaffeinated" because Ethyl Acetate (CH3CO2C2H5) can occur naturally in orange rinds and others fruits. But because of the cost of using natural extract the Ethyl Acetate used in decaffeination, a manufactured chemical is used. There is some question as to whether it is legal in the United States to call Ethyl Acetate decaffeinated coffee "naturally decaffeinated," but currently that is a common practice. The decaffeination process is essentially the same as in conventional Methylene Chloride decaffeination, except Ethyl Acetate replaces Methylene Chloride as the solvent. There are still chemical residues remaining in the coffee beans (10ppm max).

Water Decaffeination - A water process decaffeination plants starts by soaking coffee beans
in pure water. The liquid is drained off, and the coffee is thrown away, because it is now flavorless. The liquid solution, however, is full of both coffee flavors and caffeine. (Of course caffeine is water soluble otherwise they couldn't put it in your cola. The liquid is then passed through a carbon filter, which removes the caffeine but not the flavor components. This flavor saturated liquid is then poured onto a new batch of coffee. Because the liquid is already full of coffee flavors, it doesn't extract any additional flavor from the coffee beans. It does, however, extract the caffeine. This cycle of soaking, then filtering out the caffeine, can be repeated indefinitely. No chemicals are used.

Carbon Dioxide (CO2) Decaffeination - In the CO2 decaffeination process, water soaked coffee beans are placed in a stainless steel container or extractor. The extractor is then sealed and liquid CO2 is injected. The CO2 acts as the solvent to dissolve and draw the caffeine from the coffee beans, leaving the larger-molecule flavor components behind. The caffeine laden CO2 is then transferred to another container. Here the pressure is released and the CO2 returns to its gaseous state, leaving the caffeine behind. The caffeine free CO2 gas is pumped back into a pressurized container for reuse. CO2 decaffeination produces the most flavorful decaffeinated coffee. There are no harmful chemicals or byproducts of the process.

In general as a roaster, you would want to choose Carbon Dioxide decaff coffee for the best flavour