My Science Experiment

Science was never my best subject, but to be honest I’m enjoying learning the science of sourdough. Plus I get to eat my experiments!

In my last post I promised to report on my cold bulk fermentation experiment, which I did in the dead of winter (February). Instead of feeding my starter before going to bed, I fed it at 9:45 in the morning, at a ratio of 1:2:2 (30 g starter, 60 g water, 30 g bread flour). It was ready to mix at 6 p.m., but I knew I wouldn’t have time to complete the bulk fermentation before bedtime. I mixed the dough using 90° spring water, and did three stretch and folds over the next 90 minutes, then put the proofing vessel into the oven with the light on, with a cup of water alongside, for two hours. The dough temp at 10:30 p.m. was 78°. It went into the fridge, covered, and I went to bed.

At 8:30 the next morning I took it out of the fridge and recorded a temperature of 44°, which was lower than I expected; but it had risen about 25%. I popped it into the oven on the proof setting with the light on and boiling water alongside. By noon the dough temp was up to 73 and it had doubled in size, with good bubbles throughout and on the top and the jiggly character I was hoping for. After pre-shaping I let it rest for 30 minutes, then shaped it, put it in a banneton and transferred it back to the fridge, where it stayed for another 18 hours or so. The next day I baked as usual, and was thrilled with the result:
a nice ear, crunchy crust, pillowy soft crumb.

All in, the bulk fermentation took 16 hours, vs. the 7-8 it typically required. But I learned that I could manage the process to fit my schedule when I don’t have the time to push straight through. I may have been able to cut the second fermentation a bit shorter, because, based on the dough temperature, it only needed to rise about 70%. But it was a good loaf and a valuable lesson.