Feed your starter (7 - 8 am) - Discard and feed your starter about 12 hours before you are planning to mix the dough. It should be ready within that time, give or take. Your starter should more than double in size, with bubbles distributed evenly throughout.
Scald the half and half (7 pm) - Heat 166 grams of half and half with 30 grams of sugar in a small saucepan over medium heat, stirring constantly, until the mixutre is simmering and the sugar has fully dissolved. Take it off the heat, transfer to the stand mixer bowl and let cool.
166 grams half and half, 30 grams granulated sugar
Make the tangzhong - Add 100 grams of half and half to the same saucepan without washing, and sprinkle 20 grams of flour over it. Place over medium heat and stir constantly to incorporate the flour into the milk. Press out any lumps with a spatula and continue cooking until the mixture thickens into a paste. Transfer the tangzhong to a plate and spread into a thin layer to cool.
20 grams all-purpose flour, 100 grams half and half
Autolyse (7:30 pm) - Once the half and half/sugar mixture has cooled to between 80 - 90°F (27 - 32°C), whisk together flour and salt in a separate bowl. Add this to the stand mixer bowl. Use a spatula to mix until all the liquid is absorbed. Cover and let rest for 15 - 20 minutes.
260 grams all-purpose flour, 6 grams kosher salt
Knead the dough (8 pm) - Add the cooled tangzhong and 100 grams of ripe starter to the autolysed dough. Knead with the dough hook on speed 2 for 20 minutes. The dough will still feel tacky but should mostly pull away from the sides of the bowl.
100 grams sourdough starter
Bulk fermentation (8:30 pm) - Oil your hands, a bowl scraper, and your clean countertop. Scrape the dough out and shape it into a ball on the oiled surface. Lightly oil the mixing bowl, then return the dough to the bowl. Cover and place in a warm spot. You will perform 2 - 3 sets of stretch and fold at 30-minute intervals. Set a timer for 30 minutes.
Neutral oil for dough handling
Stretch and fold #1 (9 pm) - With oiled hands, lift the dough from the center. It will stretch as you lift it up and out of the bowl. If it’s too sticky, use your bowl scraper to help release it. Stretch the dough into a long strip and fold in thirds like you’re folding a letter. Turn it 90 degrees, stretch it out into a long strip again and fold in thirds. Place it seam-side down back into the mixing bowl, cover, and set the timer for another 30 minutes.
Neutral oil for dough handling
Stretch and fold #2 (9:30 pm) - Repeat the same process. At minimum, complete 2 sets if short on time.
Stretch and fold #3 + cold fermentation (10 pm) - Repeat one final set. The dough should feel stronger and more elastic. Cover and refrigerate overnight.