I don’t know the owners’ logic, but there’s a concentration of Russian Jews in the outer Richmond and that’s the only neighborhood I associate with Jewish (of various traditions, and not necessarily kosher) foods— the only giant challah in SF to my knowledge is at Moscow Tsibili across the street, (cheap) smoked fish at New World Market, bulk pickles, frozen blintzes, farmers cheese, halvah, hummus, and various Israeli goods.
