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Recently a variety of the coffee tree was
discovered that naturally contains almost no caffeine. Until that species finds
its way into commercial production, we're left with the current methods for
removing unwanted caffeine from coffee. But how do those methods affect the
taste of our java?
Blind taste tests suggest that most people can't really tell the difference
between decaf and regular, provided both kinds are processed properly and the
cup well brewed. But for those who can...
removing caffeine
Among the methods for removing caffeine from coffee is treatment with hot
water, followed by rinsing in methylene chloride.
Maybe you didn't know your coffee had already seen water before you got to it?
In fact, several times. The berries are rinsed after picking to soften the outer
fruit for removal, then rinsed again to help eliminate the remaining flesh.
And possibly you were unaware your grounds had taken a dip in the swimming pool
before being served. (Ok, swimming pool water is really dilute hydrochloric
acid, not methylene chloride. Never let a chemist stand between you
and a good line.)
So the taste difference is less likely to come from the presence or absence of
caffeine as from any remaining processing chemicals and whether they removed
flavor-producing components.
Chemical removal of the caffeine from green, unroasted beans starts by warming
them in hot water or steam. That opens the bean's pores. Then the beans are
rinsed in methylene chloride, which binds to the caffeine and is then
flushed away.
Alternatively, the beans can be soaked for several hours in hot water, where the
caffeine leaches out into the bath. The beans are removed and methylene
chloride introduced to the bath. There it bonds with the caffeine, not the
flavored components that have washed out of the bean. The beans are then soaked
again where they reabsorb the flavor compounds.
the swiss method
An entirely different process, called the Swiss method, also soaks the beans
in hot water for several hours, but no methylene chloride is used.
Instead the caffeine is removed by filtering the water through activated
charcoal. More or less pure carbon, the molecular structure of activated
charcoal has been altered to provide a large surface area for other molecules to
stick to.
The first method is less expensive and is the preferred by most manufacturers.
And -- no surprise -- there are ongoing debates about whether it degrades the
taste. As usual, quality control makes the largest difference. But there are
even techniques available to the individual for reducing caffeine intake.
Darker, less acidic, roasts already contain less caffeine as a consequence of
the roasting process. And blends of decaf and regular are an option for those
who simply must cut down.
As to the taste.... Well, as in any issue of taste, individual preferences
generally swamp any objective chemical differences. Since caffeine has an
inherently bitter taste, many can detect its presence or absence. Whether that
makes decaf good or bad is, as they say, a matter of taste.
come shop in our coffee store
Find various varieties of decaf coffees in our Coffee Store on eBay
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