It sounds intriguing! I'm glad you let us know how they came out. I am a huge fan of freshly-made corn tortillas, but find the ones we can buy in the store (even local family brands) just aren't that great. We usually end up getting a corn/wheat blended tortilla from the store and find it's quite a bit more 'tender' and flexible than pure Harina. I'm guessing the bit of flour and extra rising agent in your sourdough infused tortillas might have benefitted as well?