Otto Zahler was born in Ingstetten, Alb-Donau-Kreis, Germany to a brewing family of seventeen children. His family emigrated to America in 1857 when Otto was just 10 years old. They settled in Ramsey County, Minnesota. Sometime in the 1860s Otto went with his brother to Hennepin County to open a brewery on the banks of the Mississippi. On July 20, 1869 he married his brother William's neighbor, Christine Frey, in St Michael, Minnesota. Then in 1884 Otto with his father-in-law Frank Frey's financial backing opened a brewery in that town. They operated the brewery until 1893 when they sold it to the Dick Brothers. Otto Zahler died on June 28, 1898 at age 60 years.