Before beginning this recipe you will need to read the above article about increasing the amount of your sourdough starter and converting it to a rye starter. It's an easy thing to do but an integral part of this recipe. Sourdough in this recipe adds a tangy flavor to the bread and perfectly balances the bland taste of rye. Bread making in Poland is a very traditional task that involves home-made breads as well as breads made in bakeries. Homemade breads are generally prepared with a sourdough starter that requires a minimum of two-day fermentation. This recipe will yield two 2 lb. loaves.