1. Rye should be soaked in water for more than a whole day, so that the baked product will be soft; pour water, flour, and malt extract into the food processor, stir at low speed until the flour has absorbed the water
2. Add natural yeast, stir evenly at low speed, turn to medium and low speed and stir for about 8 minutes; add in soaked and drained rye grains and salt
3. Stir evenly at low speed; spread butter on the walls of the mold, put the finished dough into the mold, moisten your fingers, and press lightly so that there is no gap between the dough and the mold, and the surface is flattened. Cover with a lid (or put on a damp cloth), leave it at room temperature, and ferment for 15 hours
4. After fermentation, the dough has been sent to the lid of the box; put it in the preheated oven, 220 degrees, 60 minutes
