People think I'm a little srtange in the grocery store...... I smell
rye and sourdough bread to see if they have any hint of the tang I'm
looking for. Heck, the loaves are wrapped, it's sanitary, and gives me
an idea of whether the flavor is as strong as I'd like. I do the same
thing with produce - you can tell a ripe melon or pineapple by the
smell.

I agree that what you're looking for is probably 'sour rye'.