Dip 1 silver 20 kopeck coin or a silver teaspoon into 1 bottle milk and set in a warm place for 4 days. Add almost 1 glass of this silver leaven to 5 bottles of thin cream. Place the cream in a warm oven and stir as often as possible. After 4 hours, the varenets will be ready. Transfer it carefully into another bowl without the whey and set it to cool on ice. Serve with sugar and with finely pounded and sieved rye rusks.
Silver leaven may be kept on ice for about 2 weeks.