The Polish buttermilk rye bread has a mild sour tang to it. This is caused due to the sourness of the buttermilk that is used in the recipe. Not only does the buttermilk add a softness to the bread but it also eliminates the need to make a sour starter. This means that this bread is so much easier to make when compared to the other sourdough bread recipes. Here's the recipe: | Polish Foodies - The Best Polish Food Recipes