Decaffeinated Coffee

Can decaffeinated coffee compare in taste with the original caffeine edition? Caffeine is slightly bitter, but that slight bitterness combines and reacts with sugar and acid compounds to either enhance or mute other flavors and tastes.

Do the different decaffeination processes affect other flavor compounds in the bean as well?

Solvent Process

Swiss and Mountain Water Processes

CO2/O2 Process

Thoughts

Decaffeination Processes

First of all, there is no process that yields 100% decaffeinated coffee.

All decaffeination takes place at the green bean stage. The first successful decaffeination process was developed in 1903 by Ludwig Roselius and Karl Wimmer in Bremen, Germany and marketed under the name of "Kaffee HAG". The process was known as the Roselius process. By 1905, it was sold in France as Cafe sanka and was later marketed in the U.S. as Sanka. The process included steaming the beans and extracting caffeine with benzene.

Of course with the knowledge today of the adverse health effects of benzene (carcinogen), the solvent is no longer used.

Many believe that other toxic chemicals are used in decaffeination as in formaldehyde, hexane, trichloroethylene, chloroform, acetone and methanol. They either never were used or banned many years ago by the FDA.

There are two historical methods for the removal of caffeine in coffee:

• Direct Method- Steam is used to expand the beans and open the pores. They are rinsed for hours with a solvent (usually methylene chloride) to meet the EU standard of .1% or the International standard of 3% caffeine in coffee. The beans are then steamed for hours to extract the solvent.
• Indirect Method- Hot water is used to open the pores of the bean and a solvent is mixed with the water for caffeine extraction. It actually extracts most of the flavor compounds as well, so the water is sent to a tank to remove the solvent/caffeine solution using a carbon bed and then the other compounds are returned for reverse infusion into the beans.

Today, the indirect method is the most widely used.

Indirect/Solvent Process

This indirect method involves soaking the beans in hot water which removes almost all the flavor components. The water with caffeine and flavor components is separated from the beans and a caffeine specific solvent (either methylene chloride or ethyl acetate) is added to the water. The caffeine/solvent solution is then skimmed off and the water is mixed with the beans again to let the flavor components infuse into the beans. The beans are then dried to a 10-12% moisture content and are ready for market.

The differences in the solvents are:

• Methylene Chloride is perceived to play a part in depleting the ozone layer.
• Ethyl Acetate is found in fruit, so it is considered a natural substance. Beans that go through this solvent are often marketed as "naturally decaffeinated" but not always. Canada, for instance, does not allow the "natural" labeling of decaf coffee using this method. It also must be on the label that ethyl acetate was used to decaffeinate.

Organic coffee decaffeinated with methyl chloride will not keep its organic certification. It is also the cheapest process for decaffeination.

NOTE: Both solvents have a low vaporizing temperature (Methylene Chloride- 107 F; Ethyl Acetate- 171 F) so there is virtually no way there could be enough residue left from the process to pass through the +400 F roasting and 200 F brewing temps to make it to the final cup.

Swiss Water & Mountain Water Processes

The Swiss Water and Mountain Processes claim 99.9% removal of the caffeine in coffee. A patent was awarded in 1979 for a specially activated carbon and water. In 1988, the Swiss Water Process was introduced to the market in Vancouver, BC Canada.

The Swiss process starts with a hot water soak that extracts all the flavor components, as well as caffeine from the batch. The beans are discarded and the saturated water goes through the activated carbon to separate the caffeine. The water, called GCE (Green Coffee Extract) or "flavor-charged water" by the company, is then added to the next batch of beans. Since the water is laden with flavor compounds, the only component extracted from the second batch is caffeine. The flavor-charged water is used for subsequent batches.

The Mountain Water Process is much like the Swiss, but adds heated air drying at the end.

Both Swiss and Mountain processes can be labeled as natural and organic coffee will keep its certification using either process.

Bruce's Brew offers the Swiss Water Process Decaffeinated Coffee.

CO2/O2 Process

Compressed  CO2 combines easily and selectively with caffeine. In this process, the batch is pre-steamed and then bathed in supercritical CO2 (the state in which both gas and liquid CO2 properties are present) is added. The pressurized CO2 (1,000-4500 psi) is sent through an activated carbon filter to separate the caffeine or the gas is depressurized to evaporate the CO2, leaving the caffeine. 

It is very expensive to use high pressure CO2,so it is employed normally in high volume batches to be economically viable.

Organic coffee decaffeinated with this method can maintain its certification.

Thoughts

In all decaffeination processes, the beans are subjected to abuse (see picture at left- not proud of color quality, but the difference in the two is obvious). All the processes use elevated temperature, whether it be hot water or steam. With the complexity of over 400 chemical compounds in a green coffee bean and thermal actions causing chemical reactions (in roasting) to reach the desired taste of the bean, it is hard to believe that steaming and hot water baths will not have some unwarranted effect on chemical reactions.

Decaffeinated beans are also harder to roast...or at least have a different profile than the sister caffeine bean. Will the loss of caffeine in coffee beans cause the big difference in roast profiles or, are unwanted chemical reactions taking place in the decaffeination process prior to roasting?

Once the caffeine is removed, there is one less component to the bean than there was originally. Even though the slight bitterness of caffeine is not a huge taste enhancer or detractor, there is a relation between it and sweet, acidic and other compounds that no longer exists.

Without even one component of the original bean, will the taste change...even slightly?

What are your thoughts?

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