Weigh out the different types of flour and place in a tall bowl, mix in dry yeast, spices and, if desired, seeds / grains.
Warm the buttermilk to hand temperature, add the vinegar to the flour mixture and stir thoroughly with a hand mixer (dough hook) or the food processor, all ingredients must be incorporated.
Let the dough rise in a warm place (I do this in the oven at around 40 ° C) for 30 minutes. Thoroughly flour in 2 elongated proofing baskets / bread molds, add the dough and let rise for another 30 minutes.
Heat the oven to 200 ° C, turn the loaves out of the mold onto a baking sheet lined with baking paper, carefully cut three times with a saw knife and bake on the middle rail for 60 minutes. For a crispy bread crust, place a metal bowl with enough hot water in the oven during the baking process.
Take the bread out of the oven and let it cool down.
If only 1 bread is to be baked, only use half of the ingredients. But to save time and energy, I always bake 2 loaves of bread and freeze too much if necessary.