Asahi Beer Japanese signboard or "Kanban"

I am mystified as to why this signboard advertises Asahi Beer as well as something relating to sake manufacturing on the reverse side.  I am not aware that Dai Nippon Beer was also involved in sake production.  I am struggling to figure out the year this signboard was created as well as why it mentions anything regarding sake.  Please help me solve this puzzle!

Here's some history:  

Osaka Beer Company inc. began selling its "Asahi Beer" in Osaka in 1892 and merged into Dai Nippoon Beer in 1906.  The modern Asahi Breweries was created in 1949 when Dai Nippon Beer and Asahi biiru split into two separate entitties.