Sour Cream

2 cups light cream
2 Tablespoon buttermilk
Makes two cups.
Combine cream with buttermilk in hot, clean glass jar with a lid. (Canning jar that has been heating in boiling water, for instance.)
Cover tightly and shake gently to thoroughly mix.
Let stand in a warm place − like where you put bread to rise) till thickened (24−48 hours).
Store, covered in refrigerator.
Stir before serving.
Use within three weeks.