Having run out of rye bread, the two 5 pound loaves from my RV oven lasting over two weeks while on the road and during my visit to Laramie, it was time to mix up another batch of rye potato bread. There was still some fermented potato and oat flake batter left, and mixing some rye flour, salt, and a hefty glob of rye sourdough starter got another batch going. Now the tricky part began, as Sylvia's studio presented a different environment for both me and my microbes. Would the loaves rise?
Sourdough starter expands when you feed it fresh rye flour, sometimes by as much as twice its volume. The tiny lactic acid producing bacteria generate carbon dioxide gas, which inflates the dough, sort of like how the universe expands by the creation of more space. Those expanding gasses produce a surprising amount of pressure, which can easily pop the lid off a jar or yogurt container, and even shatter a glass vessel if you are unlucky. They also perform the miracle of leavened bread, which has myriad holes that give a loaf of rye bread a light texture, rather than a dense, mushy interior.
If you wait too long, the magic disappears. Many things can happen, from running out of fresh sugars and carbohydrates for the microbes to consume, to falling temperatures which can slow their metabolism. The result in either case is that they produce less gas, which can slow the rise, stop it, or even reverse the process. Perhaps every bread-maker has nightmares of loaves with sunken centers.
Sylvia's studio follows the outdoor temperature, which can reach the high sixties during the day and the low fifties or even high forties at night. My initial strategy was to form the loaves from the freshly-mixed dough and let it rise in the bread pans, since there isn't enough gas production to fuel a second rise that wheat bread bakers enjoy. Left overnight in the unheated oven, maybe they would rise to the point of baking height by morning.
My RV has a gas oven with a continuous pilot light, and that provides just enough heat to keep the bread dough warm through the night, but Sylvia's convection oven was electric and its lowest bake setting was 200 degrees Fahrenheit. That would kill the bacteria. The oven had a warm setting, but that might be too hot as well, since bacterial action peaks at 87 degrees and tapers off to nothing at temperatures over 100.
By morning the loaves were still small, essentially unchanged, so it was time to experiment. Setting the Warm function to five minutes took the chill off without excessive heat, and a few cycles of that through the morning got the loaves to expand. Then ambient temperatures rose during the day and the loaves started to look promising, with cracks forming on their curved tops.
By late afternoon the loaves looked better, but still didn't fill the pans. Would they keep going with more time? My imagination glowed with visions of full, robust loaves rolling out of the baking pans to cool on the racks. Maybe one more night would do it. After all, a little fermentation was good, so more would be better, right?
It was a gamble, with the hope that the dough had enough stiffness to hold its shape, and that the bacteria had enough food to keep producing gas, and that the temperature would be sufficient to support the process. By 3:40 AM, checking on the loaves in the oven, it didn't look good. The centers of the loaves, instead of rising to fill the pans, had fallen somewhat, as if in disappointment that they had to wait another night.
Well, the only option was to start the oven, since we had passed the peak rising stage. Thirty minutes on warm, with a rest period seemed to help, and then at 6:30 AM the 350 degree bake cycle started. The convection fan supposedly would shorten the baking time, so how about 50 minutes? Too many variables, and all of them new to me, reduced the art of baking to a guessing game.
As the baking progressed, my hopes revived, as it looked like the loaves recovered somewhat from their fallen state. They wouldn't fill the pans, but they would have a respectable shape. They also started to brown on top and look more edible, even appealing. Maybe the window of opportunity hadn't entirely closed.
Of course, it will be later today or even tomorrow before the ultimate test: slicing and toasting. Rye bread improves with age, so a little patience pays off. It is an investment in the future, one that requires attention to details, flexibility in responding to changing conditions, and a little bit of faith. After all, the microbes want to digest food and produce carbon dioxide, and the baker wants the bread to rise. All they need is a decent chance, a little luck, and determination backed with persistence.