Rustic Walnut-Buckwheat Bread with a Hint of Chestnut

In a large bowl, combine all three types of flour: spelt, buckwheat, and chestnut. Use a whisk or spoon to mix and aerate them well. Then pour in 350g of warm water (leaving 30g for later). Stir with a large spoon or your hand just until all the flour is wet and there are no dry clumps. Do not knead the dough! Cover the bowl with plastic wrap or a damp cloth and set aside for 30-60 minutes at room temperature. This process is called autolyse - it allows the flour to absorb the water, making later kneading easier and developing the gluten.

After the autolyse, add 100g of active sourdough and 20g of honey to the bowl. Using your hand, gently knead the sourdough into the dough, making 'pinching' and folding motions until the ingredients are initially combined. Let it rest for 20 minutes. Then add 10g of salt and the remaining 30g of water. Start kneading the dough in the bowl again. Grab the edge of the dough, stretch it up, and fold it into the center. Rotate the bowl and repeat this motion for about 5 minutes, until the salt and water are absorbed and the dough becomes more cohesive and smooth.

If you are using add-ins, now is the time to add them. Flatten the dough slightly at the bottom of the bowl, evenly sprinkle with walnuts and flaxseeds. Again, use the folding technique to evenly distribute the add-ins throughout the dough. Make a few folds until the nuts and seeds are visible throughout the mixture.

Transfer the dough to a clean, lightly oiled bowl or a container with a lid. Leave the dough in a warm place (about 24-26°C) for 3-4 hours. During this time, every 45 minutes, perform a series of 'folds'. Wet your hands with water, grab one edge of the dough, gently stretch it upwards and fold it into the center. Rotate the bowl 90 degrees and repeat from each of the four sides. After each series of folds, cover the bowl. You will see how the dough becomes stronger, smoother, and more aerated with each passing hour.

Gently turn the dough out of the bowl onto a lightly floured surface, trying not to 'de-gas' it too much. Shape the dough into a ball by tucking its edges underneath. Cover with a cloth and let it rest on the counter for 20-30 minutes (this is called 'bench rest'). After this time, finally shape the loaf. Flatten the ball into a rectangle, then roll it up tightly like a log to create an elongated loaf, or reshape it into a nice ball again. It is important to create tension on the surface of the dough.

Prepare a proofing basket (banneton) or a regular bowl (about 20 cm in diameter) lined with a clean kitchen towel. Generously dust the basket or towel with rice flour or potato flour (not wheat flour, as it will stick). Transfer the shaped loaf to the basket seam side up. Cover with a plastic bag or cling film and place in the refrigerator for 12-16 hours (long, cold proofing).

An hour before baking, place a covered cast iron pot in the oven and preheat it to 240°C. When the oven and pot are hot, carefully remove the hot pot. Take the dough out of the fridge and transfer it onto a piece of parchment paper. With a sharp knife or razor blade, make one deep (about 1 cm) cut along the top of the loaf or several smaller cuts. Grabbing the paper, carefully transfer the loaf into the hot pot.

Cover the pot with a lid, place it in the oven, and bake for 20 minutes. After this time, carefully remove the lid (watch out for the hot steam!) and reduce the temperature to 210°C. Continue baking uncovered for another 20-25 minutes, until the bread has a deep, dark brown color and the crust is hard. When tapped on the bottom, it should make a hollow sound.

Immediately after removing from the oven, transfer the bread from the pot to a metal rack. Leave it to cool completely, for at least 2-3 hours, preferably longer. This is an absolutely crucial step! Slicing hot bread will result in a gummy and undercooked crumb, as the 'cooking' process inside is still ongoing.