I happen to have a copy of the Gold Medal Rye Dictionary, and it is
fascinating. Combination of promotional material on Gold Medal's various
rye flours (as of 1948) and bakery-quantity recipes for a variety of ryes
along with some general rye advice.
Their "Jewish sour" includes milk, although their "Jewish white rye" recipe
allows either water or milk sours.
Coincidentally, I'm trying the Ortiz recipe right now. I've made the one
in Secrets of a Jewish Baker a few times (with good results but it takes a
longer time than I often have available), and the one that was published in
Cook's Illustrated a while back (excellent sandwich bread, not quite the
rye of my New York memories but still good).
I'll report back for anyone interested. After this, I'll try the one in
Baking with Julia, as soon as I can get two really clean kitchen towels to
make proofing slings for the rye.
Jessica Weissman
Takoma Park, MD