Soft Molasses Rye Batard with Seed Soaker

Steps

1. Feed your sourdough starter in the morning with its usual equal-weight feed and leave it at about 75°F (24°C) for 4 to 6 hours, until doubled, bubbly and domed; it must be at peak when you mix.
2. While the starter rises, toast the pumpkin seeds and sesame seeds together in a dry skillet over medium heat for 3 to 4 minutes until fragrant, then tip them into a heatproof bowl with the ground flaxseed and the oats.
3. Make the soaker: pour the boiling portion of the water (120 g) over the pumpkin seeds, sesame seeds, flaxseed and oats, stir, cover and let cool to room temperature, at least 1 hour; it will turn thick and gel-like.
4. In a large bowl, whisk the remaining lukewarm portion of the water (380 g) with the molasses and the peaked sourdough starter until the starter dissolves.
5. Add the rye flour, bread flour, coriander and salt and mix with a wet hand or stiff spatula for 4 to 5 minutes into a sticky, paste-like dough with no dry spots. The dough is about 76% hydration and 2% salt as bakers' percentages, counting the 380 g dough water against the combined 500 g of rye flour and bread flour.
6. Add the cooled seed soaker and squeeze and fold it through the dough until the seeds are evenly spread.
7. Bulk rise covered at about 75°F (24°C) for 3 to 4 hours. In the first 90 minutes do 2 sets of gentle stretch-and-folds with wet hands, 45 minutes apart; rye dough won't stretch far, so just lift and fold the edges over a few times. Bulk is done when the dough has risen about 50% and small cracks and bubbles show on top.
8. Shape: tip the dough onto a lightly wetted counter, pat it into a rectangle with wet hands, roll it up into a batard and set it seam side down on a sheet of parchment inside an oval bowl or banneton.
9. Proof covered at about 75°F (24°C) for 1 hour, then refrigerate overnight, 10 to 14 hours. It's ready when the surface shows fine cracks and a wet fingertip leaves a dent that springs back slowly.
10. Place a Dutch oven with its lid in the oven and preheat to 450°F (230°C) for 45 minutes.
11. Lift the cold batard on its parchment, score one shallow line down its length and lower it into the hot Dutch oven. Bake covered for 20 minutes.
12. Remove the lid, lower the oven to 425°F (220°C) and bake 25 to 30 minutes more, until the center reads 205 to 210°F (96 to 99°C).
13. For a soft crust, brush the hot loaf all over with the melted butter, then wrap it loosely in a clean kitchen towel.
14. Cool on a rack, still wrapped, for at least 4 hours (overnight is better, as rye crumb sets slowly) before slicing into 12 slices.