Through a calamity of events that I won't bore you with, I ended up using a UAP with more protein (12% instead of 11%) that I never used before for a lean sourdough, 76% hydration. The dough came out much more runny, very difficult for me to work (if it does work at all). Since it is  Friday night and time to party, I decided to try another and on a lark, substituted half of the water for the same weight apple cider. This batch was immediately easier to handle, and after a rest and kneading to window pane, sits plumper and more upright than any sourdough I have made.

Since there is the sugar and also a bit of "fiber" in the cider, I figured it would handle differently, but this was a real surprise. They are still rising (or running, in the first case) - could anybody give me an idea of what the mystery process is here? Oh, and also I put about 3 grams of cinnamon in the second one; the recipe has about 484g of flour in it.

Thanks for your contemplation!