Shchi

Shchi (Russian: щи; ) is a Russian soup with cabbage as the primary ingredient. Its primary distinction is its sour taste, which usually originates from cabbage. When sauerkraut is used instead, the soup is called sour shchi, and soups based on sorrel, spinach, nettle, and similar plants are called green shchi (Russian: зелёные щи, zelyoniye shchi). In the past, the term sour shchi was also used to refer to a drink, a variation of kvass, which was unrelated to the soup.