for the uninitiated ... the drinking part is about alcohol. and I can confirm that especially Freiwillige Feuerwehr orgs enjoy a firmly embedded drinking culture.
Almost all german Clubs, be it sports clubs or musician corps have a "firmly embedded drinking culture". Though it's different with the Freiwillige Feuerwehr.
The Freiwillige Feuerwehr is not a club. It's an institution of the municipality.
But some volunteer fire brigades have also a club to finance the fire brigade through donations and member fees. The members of the fire brigade are also members of the club, so they are partly paying for their own services and equipment.
In Czech/Slovak republic the Firemen's Ball is legendary once a year ball/party. Also they organize a lot of cultural/sport activities in tonw/villages. Drinking is so widespread that you don't need to distinguish the the voluntary firemen from the rest of the population :)
