Soups made of soured rye flour are an important part of the traditional cuisine of the Northern Slavs. Nowadays they are prepared mostly during the Easter period. They taste best with sausage, mushrooms and sour cream. In Poland two varieties of the soup are distinguished: white borsch made of soured rye flour and so called żur made of soured wheat flour. There are a few regional varieties of that dish, they differ in the way of preparation and ingredients. The borsch has a distinctive sour flavor, which is sometimes enriched by smoked bacon, garlic and aromatic spices, e.g. marjoram. It is traditionally served with a hard-boiled egg, sliced directly into a plate.
