Sour Cream (imitation)
Pour homemade yogurt into a strainer lined with cheesecloth and allow to drain until it is the thickness of sour cream. This will take several hours. It will drain much faster at room temperature.
The whey (drained off liquid) can be saved to use as the liquid in homemade breads. Commercial yogurt which has been made with gelatin will not drain. Store in covered container in refrigerator. For longer storage, store in freezer.
Virginia D. Nelson, "There's a Cow in the Kitchen"
Darlene Carlisle notes: Make sour cream the same way as the yogurt but use 1 1/2 times the powdered milk, i.e. for 2 1/2 cups powdered milk for yogurt, use 3fl cups powdered milk for sour cream.