How is caffeine removed to make decaf?!
Answers:
In the case of coffee, the decaffeination processes are performed on unroasted (green) beans, but the methods vary somewhat!.
It generally starts with the steaming of the beans!.
They are then rinsed in liquid that has as much chemical composition as coffee as possible (coffee has 400+ chemicals that affect the taste and aroma), except caffeine!.
The process is done 8-12 times until it meets either the international standard (removed 97% caffeine) or the EU standard (99!.9% caffeine free)!.
The process also doesn't guarantee that the other chemicals remain at their original concentrations!.
Roselius process
Steaming coffee beans with a brine (salt water) solution and then using benzene as a solvent to remove the caffeine!. Due to health concerns regarding benzene, this process is no longer used commercially!.
Swiss water process
A batch of green (unroasted) beans is soaked in hot water, releasing caffeine, then discarded!.
Next, the water passes through a carbon filter to trap the caffeine molecules!.
The caffeine-free water is then put in a device and new coffee beans are added!.
The process repeats until the beans are 99!.9% caffeine free!. The new beans are removed and dried, and thus retain most if not all of their flavour and smell!.
Direct method
Beans are first steamed for 30 minutes and then repeatedly rinsed with either methylene chloride or ethyl acetate for about 10 hours!. The solvent is then drained away and the beans steamed for an additional 10 hours to remove any residual solvent!.
Indirect method
Beans are first soaked in hot water for several hours, essentially making a strong pot of coffee!. Then the beans are removed and either methylene chloride or ethyl acetate is used to extract the caffeine from the water!.
No coffee strength or other flavorings are lost!.
CO2/O2 process
Pre-steamed beans are soaked in a liquid bath of carbon dioxide at 73 to 300 atmospheres!. After a thorough soaking, the pressure is reduced!.
The carbon dioxide is then used on another batch of beans!. This same process can also be done with oxygen (O2)!.
Triglyceride process
Green coffee beans are soaked in a hot water/coffee solution to draw the caffeine to the surface of the beans!. Next, the beans are transferred to another container and immersed in coffee oils that were obtained from spent coffee grounds!.
Decaffeinated tea
Tea may also be decaffeinated, usually by using processes analogous to the Direct Method or the CO2 process as described above!.
Caffeine content of decaffeinated coffee
Almost all brands of decaffeinated coffee still contain some caffeine!. Drinking ten cups of decaffeinated coffee could deliver as much caffeine as would one or two cups of regular coffee!.
However, in June 2004, a naturally caffeine-free bean was produced!.Www@FoodAQ@Com
It generally starts with the steaming of the beans!.
They are then rinsed in liquid that has as much chemical composition as coffee as possible (coffee has 400+ chemicals that affect the taste and aroma), except caffeine!.
The process is done 8-12 times until it meets either the international standard (removed 97% caffeine) or the EU standard (99!.9% caffeine free)!.
The process also doesn't guarantee that the other chemicals remain at their original concentrations!.
Roselius process
Steaming coffee beans with a brine (salt water) solution and then using benzene as a solvent to remove the caffeine!. Due to health concerns regarding benzene, this process is no longer used commercially!.
Swiss water process
A batch of green (unroasted) beans is soaked in hot water, releasing caffeine, then discarded!.
Next, the water passes through a carbon filter to trap the caffeine molecules!.
The caffeine-free water is then put in a device and new coffee beans are added!.
The process repeats until the beans are 99!.9% caffeine free!. The new beans are removed and dried, and thus retain most if not all of their flavour and smell!.
Direct method
Beans are first steamed for 30 minutes and then repeatedly rinsed with either methylene chloride or ethyl acetate for about 10 hours!. The solvent is then drained away and the beans steamed for an additional 10 hours to remove any residual solvent!.
Indirect method
Beans are first soaked in hot water for several hours, essentially making a strong pot of coffee!. Then the beans are removed and either methylene chloride or ethyl acetate is used to extract the caffeine from the water!.
No coffee strength or other flavorings are lost!.
CO2/O2 process
Pre-steamed beans are soaked in a liquid bath of carbon dioxide at 73 to 300 atmospheres!. After a thorough soaking, the pressure is reduced!.
The carbon dioxide is then used on another batch of beans!. This same process can also be done with oxygen (O2)!.
Triglyceride process
Green coffee beans are soaked in a hot water/coffee solution to draw the caffeine to the surface of the beans!. Next, the beans are transferred to another container and immersed in coffee oils that were obtained from spent coffee grounds!.
Decaffeinated tea
Tea may also be decaffeinated, usually by using processes analogous to the Direct Method or the CO2 process as described above!.
Caffeine content of decaffeinated coffee
Almost all brands of decaffeinated coffee still contain some caffeine!. Drinking ten cups of decaffeinated coffee could deliver as much caffeine as would one or two cups of regular coffee!.
However, in June 2004, a naturally caffeine-free bean was produced!.Www@FoodAQ@Com
It is removed in the harvesting stage, before roasting!. Yet it does not remove all amounts I believe!.Www@FoodAQ@Com