Czernina (from the Polish word czarny - black; sometimes also Czarnina or Czarna polewka) is a Polish soup made of duck's blood and clear poultry broth. In English it is referred to as Duck Blood Soup.
Generally the sweet and sour taste of the soup comes from the addition of sugar and vinegar. However, there are hundreds of recipes popular in different parts of Poland and Lithuania. Among the ingredients used are plum or pear syrup, dried pears, plums or cherries, apple vinegar and honey. Like most Polish soups, czernina is usually served with fine noodles, macaroni or boiled potatoes.
Until the 19th century czernina was also a symbol in Polish culture. It was served to young men applying for the hand of their beloved ones after the parents rejected their proposal. It is a plot element in Pan Tadeusz, a famous Polish epic poem by Adam Mickiewicz.
It is also be a regional dish in Kaszuby and Poznań.