Fine coffee learn why pure coffee is bitter.

Thomas Hoffman of the University of Science and Technology in Munich, Germany, and his colleagues broke up with the brewed coffee again.

After operating mass spectrometer analysis, Hoffman dissected one of its molecules, chlorogenic acid lactone, which is the differentiation product of chlorogenic acid (found in almost all plants). Hoffman's team then equipped a series of divergent coffees and measured the content of chlorogenic lactone separately. Although lactone will only produce gentle bitterness in mild and moderate roasted coffee, if coffee beans are roasted for a long time, the secondary differentiation products of lactone will produce strong bitterness.

Why is coffee bitter? This problem has plagued scientists for decades.

At the moment, scientists have scaled down their research and focused on two chemical molecules. At the annual meeting of the American Chemical Society, scientists stated that the two bitter chemical molecules occurred during the processing of coffee, a discovery that could lead to a shift in the coffee processing industry.