The present work deals with fruit acids and their use in chemistry class. It is divided into a theoretical and practical part. The theoretical part deals with organic acids and their chemical reactions. The work also includes sources, production and use of fruit acids. Moreover, the laws are considered among the uses in food or cosmetics.The third chapter focuses on the didactic input. Skills, competency models and curricula of secondary schools are treated. For this reason, attempts are presented and described to fruit acids in the practical part. Handouts were created for the individual experiments, especially for teachers and pupils.