Combine 50g of your RYE SOURDOUGH STARTER with 50 g warm water. Stir until most of the aged starter is broken up. Add 50 g of dark rye flour. Stir until completely combined.

Cover and set aside until bubbly and doubled in size.

In a large mixing bowl, combine 50 g of active rye sourdough starter with 245 g warm water, 45 g molasses and 25 g brown sugar. Stir until the starter has been broken up in the water, using a whisk helps. Add in 8 g of whole caraway seeds and whisk until combined.

Add 260 g bread flour and 100 g dark rye flour to the mixing bowl. Stir until all of the flour is absorbed.

Cover the bowl and set aside for 30 minutes - 1 hour.

Sprinkle 10 g of coarse kosher salt over the top of the dough and knead until completely combined - about 2 minutes. Recover and set aside for another 30 minutes.

Perform a series of stretches and folds: with wet hands, grab the dough and gently pull it until the flap is long enough to fold over itself, then fold the flap, rotate the bowl 90 degrees and repeat 4-8 times. Recover the bowl and set it aside for 30 minutes. Repeat this for a total of 3 stretches and folds over the span of an hour and a half or so.

After the last stretch and fold, allow the dough to rest, covered, at room temperature for ~6 hours, until dough is airy and smooth on top.

Scrape the dough out of the bowl onto a barely floured surface. Apply a small amount of flour to your hands and the top of the dough.

Use one hand to tuck the bottom of the dough under itself, pulling in a gentle circular motion. Preshape is done when the top of the dough ball looks rounded and smooth and feels taught. If the dough begins to tear, stop and allow the dough to rest.

Use your bowl scraper or bench scraper to carefully pick up the dough and move it to a floured surface to rest, covered with a damp towel for 20-30 minutes.

Turn the preshaped loaf, upside down on a floured surface. Fold the dough into a square-ish shape. Flip the dough one last time, and using the same technique as the preshape, tuck the dough underneath itself in a gentle circular motion until a round boule is formed.

Transfer the dough to your proofing basket, banneton, or bowl. If using a proofing basket or banneton, flour well before transferring dough. If using a bowl, line it with a flour sack towel and flour generously.

Cover the dough and rest for another two or so hours, until dough puffs up and becomes jiggly, or rest in the fridge for 12-16 hours. If performing a cold ferment in the fridge, add an extra 5 minutes to the baking time.

Place a large dutch oven into the oven and preheat together to 475f.

Once the oven has preheated, turn the proofed bread upside down onto a parchment square.

Score the dough between 1/4 and 1/2" deep.

Remove the heated dutch oven from the oven and using the parchment paper, lift and carefully lower the sourdough rye bread boule into the dutch oven.

Bake covered for 30 minutes. Remove the lid and bake for another 15-20 minutes uncovered in a 475f oven, or until the dough has browned sufficiently.

Use the parchment paper as a sling and carefully remove the cooked sourdough rye from the dutch oven and place it on a wire mesh rack to cool until room temperature before slicing.