Nonfat Dry Milk Sour Cream
["1 c. plus 2 Tbsp. dry milk", "1/2 c. very warm water", "1 Tbsp. cider vinegar", "1/4 Tbsp. salt (if desired)"]
["Place water in bowl.", "Add milk and beat with mixer.", "Add vinegar, a few drops at a time.", "Stir constantly.", "Mix until smooth.", "Allow to set in refrigerator until thick."]
["milk", "very warm water", "cider vinegar", "salt"]