Knead a pre-dough from the spelled flour, the water, the yeast and the barley malt. Let the pre-dough mature in the refrigerator for about 18 hours.
After the 18 hours, add the ingredients for the main dough and knead everything long enough to form an elastic and smooth dough. Put the dough in the refrigerator for 2 hours, after an hour press the dough flat with your hand, fold it like a cloth and put it in the refrigerator again for an hour.
Then divide the dough into 2 parts, preferably on a floured worktop and preheat the oven to 250 ° C hot air. Roll the dough and let it rest for 40 minutes, covered. Shape the dough into two baguettes and place on a baking sheet lined with baking paper, brush with water and bake in the oven for 25 minutes. Possibly put a bowl of water in the bottom of the oven.