Pour milk into sterilized 1 quart bottles.

Add 2 oz. yeast or 1 cake compressed yeast to each bottle. Cork and tie securely, set in a warm place until fermentation is well underway and lay bottles on their sides in a cool cellar. In three days, fermentation will have progressed sufficiently to allow the koumiss to be used.

This is an old recipe that was commonly used as a way of preserving milk before refrigeration.

Many health benefits have been recently associated with the use of fermented foods.