How to make
In a bowl, mix 2.7 oz (75 g) of whole grain flour - wheat or spelt with 6 tbsp (90 ml) of water. Crumble the yeast inside and mix until a mixture is obtained. Cover with cling film and refrigerate overnight.
The next day, when you are going to prepare the bread, mix the wine with the sourdough left in the fridge, pour the slightly warmed water (60 ml), the sugar and crush the remaining yeast - the 0.35 oz (10 g).
To this liquid mixture, sift both types of flour and knead the dough - smooth and elastic. Work with it for at least 10 minutes until you see distinct gluten bonds.
Shape into a ball, grease and place it in the bowl, leaving it in a warm place, covered with a towel, to rise and double in size - 1 hour.
Knead the risen dough again for 4-5 minutes and add the coarsely chopped walnuts and salt.
Shape the round bread, sprinkle with flour and decorate with walnut halves. Place it in a baking pan with a diameter of 70°F (22 cm), pre-greased or covered with baking paper. Leave it to rise again in a warm place for 1 hour and 30 minutes.
Heat the oven to 430°F (220°C), placing a fireproof bowl with water inside. The grid should be in the middle, and at the bottom position the rectangular flat tray that every oven has.
As soon as it reaches the necessary degrees, very carefully, so that you don't burn yourself, take the bowl and pour the water into the tray at the bottom. This will generate a large amount of steam.
Immediately insert the bread and bake for 10 minutes, then reduce the temperature to 360°F (180°C) and bake until nicely browned - about 30 minutes. In case the crust and the walnuts on the surface are quite dark, cover with a piece of aluminum foil to prevent them from burning too much.
Remove the finished bread, let it cool on a wire rack and cut it into slices.