|
DECAFFEINATION
PROCESSES
- This method begins by soaking a first batch of green,
unroasted beans in water to dissolve the caffeine. The
water is drawn off and passed through carbon filters to
remove the caffeine. This yields two things: beans with
no caffeine and no flavor. . . and water full of flavor
components but no caffeine.
This first batch of beans is now discarded, but the same
flavor-charged water is reused to remove the caffeine
from the next batch of coffee beans. Now, the caffeine
dissolves, but because the water is saturated with flavor
components, none of the flavors can dissolve. So the
beans simply don't lose their flavor.
The second batch of beans is now decaffeinated and ready
for drying and roasting. This cycled is repeated
continuously with new batches of beans, using the
flavor-charged water solution to remove caffeine but none
of the flavor. This method draws off 99.9 percent of the
caffeine in the beans.
- CHEMICAL-DECAFFEINATION METHODS
- Chemical methods are grouped in two categories: direct and indirect.
- As with all decaffeination processes, the direct method
begins with soaking green unroasted beans. The beans are
then flushed with methylene
chloride (DCM), a solvent that is generally used in
direct contact with the beans. As the DCM soaks through
all parts of the bean, the caffeine is drawn out.
The U.S. Food and Drug Administration (FDA) considers the
DCM residual levels in this decaffeination process low
enough to be acceptable. The FDA, however, and the
National Cancer Institute have both linked DCM to cancer
in laboratory animals. In 1989 the FDA banned DCM for use
in cosmetics and hair sprays.
Another chemical solvent used to decaffeinate coffee is
ethyl acetate - often called natural because it
exists in minute quantities in ripening fruits.
Ethyl acetate is produced commercially from ethyl alcohol
and acetic acid, which in turn may be produced from
natural ingredients or petroleum derivatives. Like DCM,
ethyl acetate is used in direct as well as indirect
contact with the beans.
In the indirect process, green beans are steeped in hot
water to dissolve the caffeine. Next, the water is
separated from the beans and treated with an ethyl
acetate solvent to remove the caffeine. Then, flavor
ingredients in the water are returned to the beans, which
are then rinsed to wash off trace amounts of ethyl
acetate. Some processors that use ethyl acetate with
water refer to their method as water process.
The use of a chemical solvent, however, clearly makes
this a chemical method.
Another consideration, of course, is the environmental
one. . . how does one dispose of the ethyl acetate?
Certainly not as easily as water, I would think.
- Another chemical-free process uses supercritical carbon
dioxide as a solvent. Here, water-saturated beans are
treated with carbon dioxide compressed to 200 times
normal atmospheric pressure. This process is primarily
used to decaffeinate large quantities of commercial-grade
coffee found in grocery stores.
THE COLORADO
COFFEE EXCHANGE USES THE SWISS WATER PROCESS OF
DECAFFEINATION EXCLUSIVELY.
Revised
April 05, 2008
|
