Brewing a solution

摘要

Coffee is big business. One conse-quence is a lot of caffeine-rich waste which cannot be thrown away willy-nilly because caffeine is a pollutant. It inhibits both the germination of seedlings and the growth of adult plants, so it must be collected and dumped at approved sites. This is a pity for two reasons. One is that it increases the cost of a cup of coffee. The other is that the waste is rich in nutrients. If it could be decaffeinated, it might be used as animal feed-thus adding to coffee companies' revenues rather than subtracting from them. But that would require a cheap way to decaffeinate it. Which is what Jeffrey Barrick of the University of Texas at Austin and his colleagues hope they have found.