Extracting caffeine?!
Extracting caffeine?
How do you extract caffeine out of coffee and tea and make them decaf?
Answers:
There are three commonly used methods, the "direct" method,
the "indirect" method, and the CO2 method.
In the direct method, beans are first steamed to soften them; they are then treated with a solvent, usually methylene chloride, or ethyl acetate. The solvent removes many of the coumpounds in the beans, including caffeine. The cafeine is then removed by "fractional precipitation", and the caffeine free solvent solution is then reused. By reusing the solvent, less of the flavors and aromas are lost from the coffee. the beans are then gently heated to dry them and remove the solvent.
In the Indirect method, water is used as a primary solvent, and ethyl acetate is used as a "secondary" solvent in order to remove caffeine from the water. The water is then reused, sans caffeine. After a certain number of batches, the amounts of flavorings and aromas in the coffee, and in the water reach equilibrium, so there is little net loss of flavor.
In the CO2 process, the steamed beans are treated with liquid carbon dioxide under high pressure, about 200-300 atmospheres. at this pressure, the CO2 becomes an excellent solvent. The pressure is then lowered somewhat, CO2 is allowed to partially evaporate, and the caffeine is seperated from the coffee residue. The CO2 and caffeine residue is, again, reused to prevent loss of flavor. The CO2 process is much more "friendly" since it uses no volatile organic compounds, but it requires much more complex and expensive equipment. This makes it less popular than the other two methods.
The term "Decaffeinated" is something of a misnomer, since decaf usually still contains some caffeine, about 10% of it's original content.
Recently, coffee farmers have begun growing a mutant variety of "Coffea arabica", discovered in europe, that naturally contains very little caffeine.
Hope that answers your question...
~Donkey Hotei
Source(s):
http://en.wikipedia.org/wiki/decaffeinat...
you cant do it yourself. They have to be steam extracted at temperatures high enough to release the oils. To do it at home would simply extract the flavor, and not the caffeine