I was a regular at Zosch for Wednesday jazz nights before I moved away from Berlin. Coming back to visit revealed that Zosch still has its old charm.
Located in Berlin's historical Jewish area, around the corner from the New Synagogue, in the charming non-renovated buildings of Tucholskystrasse (I think I found evidence of WWII gunfire on the walls), can you find Zosch. Simple wooden interior with an awesome metal bar, simple beer and wine collection, regular basic long drinks, and ok food - why should you not back out and try one of the high-end restaurants/bars of the area instead? I will tell you!
Go downstairs into the basement. If you are a smoker, you find yourself in heaven. If you are a non-smoker like me, take a deep breath upstairs and dive in regardless. What you will find after passing a fussball-table (!!) and yet another bar, and a crowd as thick as the air, is a true Berlin Unikat (unique and authentic thing).
You are now in a stone cave with rows of wooden benches all facing a small venue. The place will be packed if it's early evening and a concert is taking place. I used to come for the Wednesday night jazz band with an average age among the musician of about 65 - and a new Orleans jazz sound to die for. Like in the old days, the sound of the band fought against the sound of the chattering and drinking crowd, for there were no microphones for instruments OR voice alike. Trompet, clarinet, stand-up bass, New Orleans piano and smoky voice came completely analog and succeeded! This is remarkable, considering Zosch is the regular place for Goethe-Institute students and therfore PACKED with young people from around the world learning German and having fun.
The beer is cheap and plenty and gets brought to your seat by acrobatic waiters. But be prepared to scream your thanks and not get a response. In between try to talk to one of the pipe-smoking regulars and catch a tale or two of pre-perestroika life in Berlin. When the music is over, give the bartenders a break and say your good-byes. If you haven't gotten enough nostalgia yet, not far away is Clärchen's Ballhaus for some authentic 1940's dance-fun. But that's another story. :)
Ps: not so many glutenfree food options here unfortunately read more