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Caffeine
& Decaffeination
- Perhaps the most important thing to know about coffee and caffeine
is that the strength of a coffee’s taste has little or nothing
to do with how much caffeine it contains! While caffeine itself
has a slightly bitter flavor, our perception of strength comes basically
from the degree of roast (the darker the “stronger”)
and the ratio of coffee to water used during the brewing process
which creates the actual strength of the coffee.
- Caffeine content of a 5 fluid ounce cup of regular coffee will
range from 60 mg. to 180 mg., depending on the types of coffees
used in the blend and strength of the coffee.
- Caffeine content of a 1 and a half fluid ounce cup of espresso
coffee will range from 90 to 120 mg., also depending on the types
of coffees used in the blends and strength of the brew.
- The roasting process alters caffeine very little. It is readily
water-soluble at temperatures above 170 degrees F and consequently
is fully released into the finished beverage during the brewing.
- Caffeine varies between species of coffee trees. Arabica coffees
contain about 1% caffeine by weight in green form, while robusta
beans contain about 2% by weight.
Decaffeination
All decaffeination methods start by increasing the moisture content
of the green (unroasted) beans, in order to make the caffeine easier
to remove. A solvent is then used to extract the caffeine, and the
beans are then dried and processed for shipment to the roaster.
Solvents used for decaffeination include water, ethyl acetate, methylene
chloride, and carbon dioxide. Safe and excellent tasting decaffeinated
coffees can be produced using all of these methods. The flavor of
decaffeinated coffee depends on the quality of the beans used, the
specific blend, and roasting technique, as well as the decaffeination
method. Your specialty coffee retailer will be happy to recommend
decafs that may well prove superior in flavor to any coffee you’ve
previously had, whether with caffeine or without!
All decaffeination methods must remove 97-99% of the caffeine
present in order for the coffee to be sold as decaffeinated. This
is 97-99% of the original caffeine content, meaning that decaffeinated
coffees are, for all practical purposes, caffeine-free. While a cup
of regular coffee might contain 100 mg. or more of caffeine, a typical
cup of decaf contains less than 3 mg.
There are many different types of roasting equipment available,
varying widely both in size and in operation. Most common is a machine
which resembles an oversized clothes dryer, in which the beans are
constantly kept tumbling through the use of a series of vanes inside
the chamber. With this type of equipment the coffee’s development
can be monitored through the use of thermometers and visual inspection
of the coffee itself, through the use of a small trowel-shaped tool
called a “trier,” which is used to draw a small sample
of beans from the chamber as they are roasting.
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