Coffee Decaffeination Methods
are essentially three main methods used to decaffeinate coffee;
water-processed, chemical solvent processed, and the most
recently devised method is the C02 process. Below are brief
descriptions of each.
Processed. The most common of water-processed
coffee decaffeination is the patented Swiss Water
Process. There are others such as Royal Select Water
process. Both are similar in that no chemicals are
used to decaffeinate the coffee beans.
beans (green coffee) are placed under pressurized,
heated water which circulates through them causing
the beans to absorb the water and swell. The pores
of the coffee beans open, allowing the caffeine to
wash free of them. The now resulting aquafied, caffeinated
substance is run though a series of activated carbon
filters, thus indirectly removing the caffeine from
the coffee beans. The remaining substance is flavor-charged
water (without caffeine), and is circulated back into
the beans which adds the flavor back into the coffee.
Next, the beans are dried, polished, bagged and made
ready for shipment to the roaster.
Method - (methylene
chloride and ethyl acetate) - Okay,
this sounds a lot scarier than it is. While neither
of these methods has been labeled unhealthy by the
medical establishment, Methylene chloride is a chemical
that has been implicated in the depletion of the Earth's
ozone layer. Ethyl acetate is found naturally in fruit,
and such you may see coffee by this process called
natural processed or naturally decaffeinated.
Keep in mind that both of these chemicals are very
volatile (they evaporate easily) and therefore it
is very unlikely that any residues survive the high
temperatures of the roasting and brewing processes
that occur before the coffee is actually consumed.
Nevertheless, consumers concerns and fears of such
substances have led to the development of the other
processes. The solvent method is also called such
names as European Process, Traditional Process,
and Conventional Process.
process itself goes something like this: Moistened
coffee beans are soaked in water and pressurized in
a steam environment. The beans swell making the caffeine
accessible to extraction and are then placed in contact
with the chemical. Once the desired decaffeination
level is achieved (typically 99% or better), the beans
are removed, dried, and are ready for roasting.
Dioxide or C02 Process - A
vital element and important compound of our natural
environment is carbon dioxide. It is in the air we
breath, it is also the gas that makes mineral water
effervescent, and by assimilation it enables plants
to grow. It is also a highly selective solvent for
caffeine. In this patented process, the natural carbon
dioxide is used under sub-critical conditions (in
a liquid state at low temperature and pressure, relative
to the super-critical process). These process parameters,
together with the exceptional caffeine selectivity
of CO2, make for a high retention rate of coffee components
responsible for aroma and taste. The process can be
described as follows:
coffee beans are moistened with water and put into
a vessel where it is in contact with pressurized liquid
carbon dioxide. By circulation through the coffee,
the carbon dioxide draws the caffeine out of the beans.
In an evaporator the caffeine precipitates from the
CO2, which after evaporation and re-condensation is
pumped again into the coffee-containing vessel for
a new cycle. When the required residual caffeine level
is reached, the CO2 circulation is cut short and the
coffee is discharged into a drier where it is gently
dried to about the original moisture content. After
that the coffee is ready for roasting.
specific characteristics of the Natural Liquid Carbon
Dioxide Coffee Decaffeination Process are:
compounds responsible for flavor and taste development
in the roasted coffee are practically left intact
(this is especially beneficial for high-grade coffees).
as "organic" and "Kosher" by
life is about the same as regular "caffeinated"
green coffee beans.
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