Michigan Breweries History: Geyer Brothers Brewing Company Geyer Brothers Brewing Company started out in 1862 as the Heubisch & Knaust, Cass River Brewery. In 1874 Johann Geyer purchased the Cass River Brewery and renamed it Geyer's Brothers Brewing Company. Geyer Brothers Brewing closed for prohibition from 1928 to 1933 at which time it opened again as Geyer Brothers Brewing Company. In 1987 Geyer Brothers Brewery was purchased, remodeled and opened as Frankenmuth Brewery. The Frankenmuth Brewery (The Geyer Brothers brewery building) was severely damaged by a tornado on June 21, 1996, and all brewing, bottling, retail, and tour operations stopped. However, they've built a brewpub on this site, and they reopened in June 2003 as the Frankenmuth Brewery.