Guide to Decaffeinated Coffee

Caffeine was first discovered in 1820 and since that time scientists have looked for ways to remove it. The problem has always been preserving the taste of the coffee while removing the caffeine. Today, there exist several effective methods of achieving this.

What is the origin of decaffeinated coffee?

Around 1900, Ludwig Roselius, a coffee merchant from Breman, Germany began working on a decaffeination process. He used benzene as a solvent to bond with caffeine molecules. The benzene-caffeine could be boiled away, removing the caffeine. Roselius described his process as "sans caffeine" which he shortened to the familiar name "Sanka". Roselius moved to the United States in search of greater opportunity, but his company was seized during World War I under the U.S. Alien Property Custodian Act. General Foods acquired Roselius' procecss and trade name in 1932 and made "Sanka" a household word in the U.S. and around the world.

By what process is the coffee that Wilson's sells decaffeinated?

We currently sell coffee decaffeinated either by the Swiss Water Process or Mountain Water Process, a decaffeination method based on the Swiss Water Process. Both of these are non-chemical decaffeination processes.

What do the Swiss Water Process and Mountain Water Process entail?

The process begins with a batch of green coffee; the beans are immersed in pure, very hot water and placed under great pressure. Caffeine is water soluble and so escapes from the beans into the water bath. Unfortunately, so do the molecules which give coffee its flavor. Eventually a water solution saturated with the flavor elements of the coffee is created; because of this, it cannot absorb any more flavor molecules.

Once this has been achieved, the caffeine in the solution is removed with an activated carbon filter. At this point, the coffee beans are removed from the water bath and replaced with new green coffee. Since the water bath is already saturated with flavor, it is unable to absorb any more and the taste of this second batch of green coffee is nearly unaffected. Since the caffeine has been removed from the water bath, the caffeine in the second batch is free to escape into the solution where it, too, will be removed by the carbon filter. The second batch of green coffee is now ready to be removed from the water bath and dried. The first batch of green coffee, used to create the flavor charged solution, is discarded because it is totally devoid of flavor.

What are some of the other decaffeination processes used in the coffee industry?

Today, the two most popular chemical decaffeination processes use methylene chloride or ethyl acetate. Wilson's does not sell coffee decaffeinated by either of these processes. This coffee is, however, readily available at any grocery store. Both processes have been proven safe for the consumer. There are also processes that use CO₂ to remove caffeine.

What does the Methylene Chloride Process entail?

This process involves submerging the green coffee beans under continuously running hot water. The water becomes filled with caffeine molecules; it is then drained and blended with methylene chloride. Methylene chloride binds easily with caffeine molecules. The caffeine-chemical complex boils and vaporizes at 114°F, so removing the caffeine and the binding solvent requires only heating the water. After heating, the water is again passed over the coffee beans and the process is repeated until decaffeination is complete. This process is known as an indirect method, since the methylene chloride never comes in direct contact with the coffee beans.

Methylene chloride is a known carcinogen and highly toxic; simply handling it can be deadly. Nevertheless, the chances of getting methylene chloride poisoning from coffee are so small as to be nonexistent. This is because the chemical boils at such low temperatures that it is easy to remove it from the green coffee. Furthermore, coffee is roasted at over 400°F and brewed near 200°F so all traces of the solvent are effectively removed from the final cup. Methylene chloride is also recovered and reused for future decaffeinating operations, making the process environmentally sound.

The real danger of the methylene chloride process is to the men and women who work at the decaffeination plant. These plants feature ventilation systems, respirator masks, and special clothing to protect their workers.

What does the Ethyl Acetate Process entail?

In this process, green coffee is exposed directly to ethyl acetate which readily bonds with the caffeine molecule; the resulting solvent-caffeine is boiled away. Ethyl acetate boils and vaporizes at 104°F. Once again, the danger of this process is at the plant; ethyl acetate is an extremely flammable chemical that needs to be handled with extreme care.

Coffees labeled with the words, "naturally decaffeinated", are usually decaffeinated by this process. There is nothing natural about decaffeination, regardless of the process, but ethyl acetate is not known to be a health hazard and occurs naturally in some fruits, including coffee cherries.

What does the Hypercritical CO₂ Process entail?

When carbon dioxide gas is cooled and placed under pressure, it becomes a liquid. In this state it is able to bind with the caffeine molecule, leaving flavor elements inside the green coffee unchanged. Green coffee is soaked in containers of liquid carbon dioxide until the caffeine is soaked out. This process is also extremely industrial and requires heavy duty cooling equipment, with the pressure supplied by large centrifuges. Purity of the coffee is assured because of the extremely low boiling point of carbon dioxide.

Why has Wilson's chosen to stock coffee decaffeinated with non-chemical processes?

There is really nothing "natural" about decaffeinating coffee. While we believe the chemically decaffeinated coffees available today to be safe for the consumer, we have chosen to sell non-chemically decaffeinated coffee because of the environmental hazards the chemical solvents present.