How do they make decaffeinated coffee?
Question
How do they get the caffeine out of decaffeinated coffee and tea?
John, London
Answer
** Definitive **
Name: Russell
Qualification: Degree in chemistry - and in the first year at uni, I did this very experiment
Answer: For coffee, caffeine is extracted using hot water. You dissolve coffee in water and the caffeine goes in the hot water - although obviously so does a lot of flavours and oils and such. So the dissolved water is passed through a carbon filter, which only removes the caffeine. The hot water is then combined back with the original coffee remains and you end up with coffee that tastes like coffee, but without the caffeine. Tea is similar, but you don't always use water - sometimes solvents are used.