Sourdough
Ideally you get the sourdough from the person who explained to you
the art of making rugbrød. If
this is not possible, do the following:
Mix
-
1 cup rye flour (Hodgson Mill)
-
0.6 cup buttermilk
-
1/2 teaspoon salt
Cover with plast foil and let sit at room temperature 3-4 DAYS (until
it smells a little sour).