After the end of the First World War, Hubert was called to complete his compulsory military service as a solider stationed in Germany. There he learned about German brewing methods and styles. Upon his return, Hubert returned to brewing both lambic as well as top-fermented beers. His top fermented beers eventually became popular under the name Hert Ale, and he decided to sell his gueuze under the name [[Brasserie De Keersmaeker | Gueuze Den Hert]] which lasted until 1971.
[[File:MortSubite-SpontaneousTanks-1.jpg|thumb|left|Sponteanous fermentation tanks at Mort Subite]]
Throughout the middle part of the 20th century the [[Brasserie De Keersmaeker | De Keersmaeker]] family both farmed and brewed. In 1936, a completely new brewing system was ordered. By the time it was ready, World War II had broken out and Hubert managed to hide the as of yet uninstalled kettles under piles of straw when the Germans invaded in the spring of 1940. As was common in many of the small villages, the brewer also became the mayor. Hubert was elected Mayor of Kobbegem in 1932, and remained in office until his accidental death in 1945.