"In 1933 after the repeal of of Prohibition, the Clyffside Brewing Company took over the old Mohawk Brewery buildings on McMicken, Stonewall, and Mohawk Streets. The new company was organized by Paul Esselborn who had attended the Royal Bavarian School of Brewing in Germany.
In 1937 the old Sohn homestead was razed and a brown brick addition was built on McMicken Avenue. Another addition was constructed on Mohawk Street in the same style. Both these buildings bear the name Felsenbrau. It was the name of Clyffside's beer. It was meant to denote that the beer was 'brewed in the rocks' or at least stored in the hillside tunnels.
By 1940 C. Howard Knapp was president of the company and he was assisted by Ivan Fischer and George Koenig. By then about 150 men worked at the brewery which produced beer and ale.
The new additions housed the bottling plant and modern fermentation tanks. Refrigeration equipment was added to keep the tunnels even colder than they were naturally. The 1930's era buildings still stand along with the old Sohn structures.
In 1945 the brewery was sold to the Red Top Brewing Company."