Weinerei Forum is a nice place in Berlin Prenzlauer Berg. It is a Wine Bar. But a very special one.
You pay in the beginning 2 EUR for an empty glass. At the Bar there are always between 4 and 8 bottles of Wine. Always Wines from the Region. There are no foreign Wines. You can refill your glass as many times you want and you have to count yourself how many times you refilled your glass. In the end you pay for every refill you counted 2 EUR.
The whole system is based on trust. Theoretically you could drink 10 glasses and just pay for 5. And if everybody would do that they would go bankrupt pretty fast. But surprisingly the system works and Weinerei Forum is out there since many years.
From time to time they serve Food, too. The concept is the same.