In winter, yogurt is prepared quickly as follows. Mix 3–4 bottles whole milk and several spoons fresh sour cream and set in a warm place for 24 hours. When it thickens, cool and serve with sugar and crumbs of finely pounded, dried black bread. In summer, it may be prepared in 24 hours even without sour cream, but before serving, it should be cooled on ice. Serve with sugar and rye rusks.