The Polish Kitchen: Żurek (Sour Rye Soup)

cybermud wrote: Sounds like the sour cream and vinegar are meant to replace the fermented rye flour.

I would guess so. I've seen Polish Easter soup recipes where, instead of the fermented rye sour, they substitute vinegar, lemon juice, or even pickle juice. I like the gentle, lactic sourness of zurek, so I'm not a fan of vinegar as a substitute, but it will certainly work in a pinch. I seem to recall my mother occasionally spiking her zurek with vinegar when it wasn't tart enough for her tastes.