In the brewing process of Nanguo pear, the sugar in Nanguo pear is converted into ethanol by fermentation, and some other compounds, such as esters and acids, are produced at the same time, which is a typical example of chemical reaction, so it belongs to the type of chemical change.

In chemical reactions, the structure and composition of substances have changed, and valence bonds or ionic bonds between molecules have been broken, leading to the formation of various new substances.