Coffee beans roasted more bitter, what other factors affect the bitter coffee?

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The bitterness of coffee has always been controversial. Some people say: how can it be called coffee if it is not bitter? Some people say: good coffee has a pleasant bitterness. There are many people say: good coffee should not have a bitter taste! Suffering is not good!

And why on earth is coffee bitter? It is thought that caffeine is responsible for the bitter taste of coffee, but in fact, caffeine accounts for only 10% of the bitter taste. The concentration of caffeine in roasted beans is not affected by the degree of roasting, and decaf coffee also has a bitter taste, so we can be sure that caffeine is not the whole cause of bitterness. So what is the other 90% bitterness?

One of the root causes of the bitterness of coffee is brown pigment. Brown pigments are also roughly classified according to molecular size, and macromolecular brown pigments are more bitter. With the deepening of the baking degree, the amount of brown pigment will increase, and the proportion of macromolecular brown pigment will also increase. So deep-roasted coffee beans are more bitter and textured-which is consistent with our daily impressions.

The bitterness and texture of Arabica and Robeska are different, which is caused by the difference in the quantity and molecular size of brown pigment. Because the sugar content of Robeska is lower than that of Arabica, it is not easy to "caramelize", so it is easy to form macromolecular brown pigment, so the baked Robeska is more bitter.

A research team led by Professor Thomas Hofmann, a food chemist at the University of Science and Technology in Munich, Germany, deeply explored the bitter factors of coffee. With the help of high-tech chromatographic analysis technology and molecular sensory technology, and with the help of a group of professional taste testers trained for many years, Hoffman's research team confirmed that chlorogenic acid lactone and phenyllindane were the two most bitter compounds in coffee.

Hoffman points out that chlorogenic acid itself is not bitter and is a beneficial antioxidant, but its degradation products chlorogenic acid lactone and phenyllindane in the baking process are very bitter. Scientists have identified the bitterest ingredients of coffee and are now working on how to remove the bitter parent chlorogenic acid from raw beans, or how to remove chlorogenic acid lactone or phenyllindane from coffee drinks to make coffee more palatable. However, once successful, it means that there are no more antioxidants in coffee that are beneficial to the body. Whether it is a blessing or a curse still needs to be considered.