In the evening:
100 g rye sourdough
3 dl water
3 dl strong bread flour

500 g peeled, grated apple
1 dl Dansukker Dark Muscovado Sugar

200 ml crushed rye
3 dl boiling water

In the morning:
Sourdough, apple mixture and soaked crushed rye
7 dl strong bread flour
2 dl rye flour
2 dl buckwheat flakes
2 dl sunflower seeds
200 g walnuts
1 dl linseeds
1 tbsp aniseed and fennel seeds
3 tsp salt

Recipe for sourdough can be found here

Mix the sourdough and water in a bowl and stir in the flour. Cover with a lid or clingfilm. Leave to stand at about 25 °C overnight, for instance in the oven with the heat turned off. Mix the grated apple with the muscovado sugar and place in the refrigerator. Put the crushed rye in a bowl, cover with boiling water and leave to soak. In the morning, combine the sourdough, apple mixture and crushed rye mixture in a large bowl. Add the remaining ingredients and mix thoroughly. Cover with clingfilm and leave to rise until doubled in size (2-3 hours). Divide the dough between two greased rectangular bread tins measuring 2 litres each. Sprinkle the loaves with a little rye flour. Leave to stand for 1 hour. Put the loaves in the lower part of the oven at 250 °C. Reduce the temperature to 200 °C and continue baking until the bread has an internal temperature of 98 °C. The bread will take about 1 hour to bake. If the internal temperature is lower, the bread will be soggy. Turn the loaves out of the tins and leave on a wire rack to cool.