Forgot to add:
The classical drinks to a Flammkuchen in our area are sour ones:
a Speierling which is a sort of cider from very sour apples and some fruits from service tree which are called Speierlinge here. Actually, having our own service trees, we make normal Apfelwein and add Speierling juice wheb serving. So the vitamins and medical properties of the service fruit stay
or after the grape harvest a Federweißer, which is not yet ripe wine with lot of yeast. The bottles have a special lock which works like a valve to let the gases out. The bottles have to be moved and stored standing, else the valve will be filled with the liquid and all results in a big mess with Federweisser everywhere in the room.
"Federweißer contains yeast, lactic acid bacteria, and a large amount of vitamin B1 and B2"
Kids drink them in a ratio of two or three parts sparkling water and one part of beverage.