At the same time, make the yudane by combining the rye flour with the boiling water in a heatproof bowl. Mix quickly with a whisk or chopsticks to hydrate as much of the flour as possible. The mixture should thicken into a paste. Cover the scalded mixture, let cool to room temperature, then place in the fridge until ready to use.

In a stand mixer, combine the stiff sweet starter, the yudane, and all of the final dough ingredients EXCEPT for the butter. Mix until well combined then let sit for 20-30 minutes.

Mix on low-medium speed for 5-10 minutes until moderate gluten development, then add the butter, one slice/knob at a time, letting each knob be incorporated before adding the next. Mix until the dough passes the windowpane test.

Bulk ferment at 2-4 hours at 82 degrees F. OPTIONAL: chill the dough in the fridge overnight – final fermentation will take longer if you do this (around 6-8 hours for me).

Prepare the pullman tin by greasing lightly with butter or oil, or lining with parchment paper.

Divide the dough into 4 equal parts, shaping each into a ball. Greasing your countertop and your rolling pin lightly, roll out each ball then fold into a rough rectangle. Turn 90 degrees, then roll out each rectangle into a 6” by 8” rectangle, keeping it neat as much as possible. Letterfold from the sides so that the edges meet in the middle. If they do not meet, pinch the edges lightly together and roll the dough lightly some more to seal the seam. Now the dough should be a 3” by 8” long rectangle. Starting from the top, roll this tightly into a roll. Place the roll seam side down into the pullman. Repeat with the remaining dough. Arrange the rolls so that the swirls alternate directions.

Proof for 4-6 hours at a warm temperature. If you have a dedicated proofer, ferment at 82F. If you do not, preheat your oven for 1-2 minutes until it reaches that temperature, turn off the oven, then place the loaf in the oven. On sunny days, I like to leave the covered pullman outside in a sunny spot. When ready, the dough should come around 1 cm of the top of a 4x4x9” pullman pan. For a 5x5x10” pullman, the dough comes to around 1 inch to 1.5 inch close to the top (each lobe may be different).

Preheat oven to 355 F. Bake at 355 F for 50 minutes without the lid. Turn out the bread soon/immediately after baking and cool on a rack to avoid condensation. Cool completely before slicing.