1 The day before serving, mix 150 grams (approximately 1/2 cup plus 1 tablespoon) total of combined flours, make a well in the center and crumble the yeast into well.
2 Pour 200 ml (approximately 3/4 cup) warm water into the well. Using the dough hook of a hand mixer, beat on low speed until mixture forms a dough, about 5 minutes.
3 Turn out dough onto a floured work surface and knead by hand for an additional 5 minutes.
4 Form dough into a ball and place in a lightly oiled bowl.
5 Turn dough to coat with oil. Cover bowl with plastic wrap and let dough rise in a warm spot for about 1 hour.
6 Lightly knead the dough again. Cover and refrigerate for 12 hours.
7 Cut the dough into 8 equal pieces. Cover with a floured kitchen towel and let rise in a warm spot for about 40 minutes.
8 Mix remaining flour and 1 teaspoon salt in another bowl. Add the starter dough, malt extract and 200 ml (approximately 3/4 cup) warm water and knead for 5 minutes with the dough hook of hand mixer.
9 Turn out dough onto a floured surface and knead for 5 minutes by hand.
10 Place dough in lightly oiled bowl and turn to coat. Cover bowl with plastic wrap and let dough rise in a warm spot until doubled in bulk, about 1 hour and 40 minutes.
11 Gently turn out dough onto floured surface. Cut dough into 2 equal pieces and gently shape into 2 round loaves.
12 Place each loaf on a large piece of parchment paper, cover with a kitchen towel and let rise in a warm spot until increased by half. Heat a baking sheet on the lowest rack of preheated oven at at 250°C (fan 220°C, gas: highest mark) for about 4 minutes. Place loaves with parchment paper on hot baking sheet. Pour 100 ml (approximately 1/2 cup) water onto oven floor and close the door immediately. Bake for 15 minutes. Reduce temperature to 180°C (fan 160°C, gas: mark 2-3) (approximately 350°F) and bake for another 20-25 minutes. Remove from oven and cool completely on a cooling rack before serving.