Underberg is a digestif bitter produced in Germany by Underberg AG, made from aromatic herbs from 43 countries, which undergo inspections and are based on a secret Underberg family recipe whose members are personally responsible for the production of the drink. Underberg is one of the most widespread kräuterlikörs on the market. Underberg contains 1.3 percent herbal extract by weight, which include aromatic, digestion-stimulating, relaxing and calming active substances, and naturally occurring vitamin B1. The drink matures in Slovenian oak barrels for several months to enhance the flavor.
It is based on a secret and proprietary recipe, guarded by the Underberg family since the company was founded by Hubert Underberg-Albrecht in 1846. The herbs are distilled using a process called semper idem (or "always the same"). The extracts are then matured for months in barrels made of Slovenian oak.
Production ceased in 1939 due to lack of raw materials, and was restarted in December 1949. The drink is usually associated with its portion-sized 20 ml bottle, designed in 1949 by Emil Underberg, grandson of the founder. The mini-bottle is protected by a straw paper sleeve, and the embossed Underberg label is glued on. All of its elements, including shape of the bottle, colour, packaging and the Underberg name are trademarked and copyrighted.