Serving in the U.S. Army in Germany, I always meant to get to Berlin. It never happened, so, in the meantime, I try to exact the science of a "kurz sauer, a sourdough Berliner bread. It's a path towards baking mildly acid loaf bread with a bit of commercial yeast, and one which is fairly quick.
I'd already made a loaf without the added yeast, which, in effect, make it more of what's known as an "ein bisschen länger sauer," (a bit longer sourdough). I've used Nils version, still suffering from a learning curve with Dieter Buschman's sauerteigrechner (calculator for sourdough). If you're in a pickle for time, and you can imagine a bread perfect for sliced Westphalian ham or leberwurst, this is a good pick. A bit tacky from the amount of rye starter, but it's a friendly loaf from the mix to final bake.