Saturday morning was around -9F (-23C) where I was this past weekend and I was trying to bake a rye. The kitchen was reasonably comfortable -- around 70F (21C). But the dough wouldn't respond. I baked 2 suspiciously biscuity breads before I realized that, when outdoor temperatures get this low, humidity naturally dives toward the single digits, and objects don't hold heat well even if the indoor air is relatively warm. For the 3rd loaf, I used a much higher inoculation for the preferment (30% instead of 8%) and let the final dough go for 8 hours on the counter instead of 3. Also, total hydration needed to be higher than usual -- somewhere around 85%. And this was the beast I pulled from the oven. Sorry no crumb shot: I gave the boule to a friend.
Rob