New Process
For this loaf I tried a different process.
Starter: 25g unbleached bread flour, 25g whole wheat, 50g water, 1/8 tsp yeast. (100% hydration)
Dough: 300g unbleached bread flour, 240g whole wheat, 60g dark rye, 480g water, 12g salt. (80% hydration)
The three dough flours were mixed with just the water. After two hours, I did some stretch and folds. At this point I mixed the starter. After another hour I did some more stretch and folds and added the salt and starter to the dough. During the next two hours I did two more stretch and folds, and then put the dough in the refrigerator. In doing the stretch and folds I added, at least, 30g of water.
After 17 hours in the refrigerator the dough was left on the counter for another three hours. There were three stretch and folds during that time. Preshape, bench rest, and final shaping took another hour. Total time, including baking, was about 28 hours. Final hydration was about 86%