Czernina is a type of Polish soup that incorporates duck blood along with the meat of the fowl, spices and dried fruits. There are many variations on the recipe in Poland, where it's not uncommon for a family to have a unique recipe with a unique list of ingredients. It can take several hours to make the soup, with most of the time spent boiling the duck meat to draw out as much flavor into the liquid as possible. The soup is usually served with egg noodles, regular flour noodles or potato dumplings cooked in the broth. Some versions of czernina are known as blind czernina and do not include blood in the dish, and some recipes may forego the duck entirely in favor of other types of meat.
One factor that helped to form the recipe for czernina is the sparseness of resources during certain periods in the history of Poland. The soup uses nearly every edible part of the duck to create a hearty meal that can be flexibly extended with accompaniments such as pasta, bread or dumplings. This lack of waste means the traditional recipe calls for a whole duck, its internal organs, the blood and bones — basically every part except the head. The ingredients were toned down as food became less scarce, so some versions call only for thighs or legs and no blood.
The traditional dish is prepared by first mixing duck blood with some vinegar to prevent it from coagulating. Meanwhile, the butchered duck — including its internal organs and parts such as the neck and feet — are placed in water with salt, pepper and a spice mixture wrapped in cheesecloth. The spices traditionally used in czernina vary widely but generally include parsley, rosemary, thyme, allspice and cloves. After boiling the duck and spices for anywhere from one to six hours, dried fruits are added.
The dried fruits added to the czernina typically include prunes and apricots. Some recipes call for a variety of dried fruit, including apples, cherries, raisins and plums. Not everyone likes the taste of the dried fruit in the dish and omit it completely.
When the soup is done cooking, the heat is turned off, the meat is removed from the pot and the bones are removed. The duck meat is placed back in the soup, along with either flour or a cream and cornstarch slurry, to begin to thicken the stock. The blood is then added to the soup along with some sugar if the dried fruits were not added. After boiling the entire soup until it has thickened, the czernina is done.
A few alternate versions, called blind czernina, have risen in popularity. These may use prune juice instead of duck’s blood, and pork or beef ribs instead of duck. Some recipes actually call for very little blood, so the prune juice is used instead to approximate the dark color the blood would have imparted to the dish; the flavor of the blood is not missed because so little was called for to begin with.
The completed soup can be served over egg noodles or pasta. Dumplings made from raw potatoes can be dropped into the soup during the final minutes of cooking. Another option is to serve it with a spoonful of sour cream in the middle of the bowl to accent the sweet and sour taste of the soup.