Since I've got my rye levain perked and regularily refreshed these days, I decided to use Dieter Buschman's Sauerteig rechner ( sourdough calculator). Perhaps I'll try various percentages of rye/wheat till I get to a total of 100 percent rye. In the meantime, my latest is a 60 percent rye and 40 percent wheat. I used a 50/50 mix of white whole wheat and white all-purpose flour, along with medium rye in the final dough. Just out of precaution and time (it was a late night bake), I used yeast along with the sourdough.
The result? A moist loaf and a perfect foil for butter and ham. On my next try, I may do without the yeast and go all white whole wheat. Or I might even do use bread flour which could give it a bit more structural strength. Mind you, I like the rustic flavor and texture as it is, but you can always tweak bread, give or take a percent.