Step 1

Soak the seeds in hot water the night before it's time to bake. Place the seeds in a pan or other heatproof container and pour over boiling water. The water shall cover all the seeds. Cover with a lid and let the mixture sit overnight.

Step 2

Prepare a levain by mixing 200 grams of water, with 250 grams rye flour and 80 grams mature sourdough starter. Let it ferment overnight, approximately 8 hours in room temperature, about 71ºF/21ºC.

Step 3

Drain the seeds through a strainer and mix with the levain and the rest of the ingredients.Mix thoroughly so that the seeds are distributed throughout the dough, and so that there is no dry flour left.

Step 4

Let the dough bulk ferment for 4 hours at a temperature of 71ºF/21ºC. If you want a more sour taste you can let it ferment longer in a colder environment, but be careful. The taste can become a bit overwhelming.

Step 5

Distribute the dough into two bread forms that you have oiled and sprinkled with a thin layer of flour. Use a fine strainer or a sieve.Smooth the surface with a spatula.

Step 6

Let the dough proof for 5 hours at a temperature of 73ºF/22ºC. It should rise about 25-30% of its initial volume.

Step 7

Preheat your oven to 480ºF / 250ºC. You don't have to bother about steam when baking this bread. But it requires some time in the oven, at least 90 minutes. Bake on the high temperature for 20 minutes, then turn it down to 390ºF / 200ºC.It's a good idea to place an extra oven plate over the bread. That will prevent it from being burned on the top.Check if it's ready with a thermometer. The internal temperature should be about 215ºF / 100ºC.Turn the oven temperature down to 215ºF / 100ºC, but don't turn it off.

Step 8

Let the bread cool in the form until you can handle it. Take the bread out of the form and place it in the oven again for about 5 to 10 minutes. That will create a crust on the sides and the bottom of the bread that will prevent it from molding.