TRB Cumin Rye
I baked the Cumin Rye from the Southern Polish chapter of "The Rye Baker". The recipe calls for light rye, but I used KA medium rye (70% without adjusting the 65% hydration).
It's got a very nice flavor with a hint of cumin (1%, toasted and ground). The final dough was unusually easy to shape, almost like a wheat dough. It occurred to me later that substituting medium rye for the light rye in the formula probably should have had higher hydration as well. That accounts for the tight crumb (described in the book as airy).
TRB Cumin Rye 70% Medium Rye @ 65% Hydration
One aspect of TRB recipes is that to match the volume increases and timings I need to ferment and proof the sourdoughs at higher temps than he suggests (almost always 68 - 72 F). My starter needs at least 76 F to get close; generally I get virtually no volume increase for his 10% sponges (but the final dough bulk fermentation is usually better). I'd go even a bit warmer to encourage the yeast but it might discourage the LAB, especially acetic acid.
That's a very nice loaf. The crumb looks ideal for sandwiches. Your crumb looks very similar to a loaf made with light rye in pictures of this bread on a Polish site. I think i's the same recipe that's in TRB.
How did you like the cumin in the bread? That seems unusual for a Polish recipe. Ginsberg may have erred in the translation of kminek (probably should be caraway).