This homemade yogurt is thick and creamy. Made with a base of natural yogurt, the addition of milk and powdered milk make for a thick yogurt with a luxuriously rich texture. Allow plenty of time for this recipe as the yogurt needs to bake for 3 hours before being refrigerated for 3 hours. The yogurt can be made with cow's milk, sheep's milk, goat's milk, or even soymilk. The milk can be any variety, except the use of skim milk requires a thickening agent such as powdered milk. It is easiest to make your own yogurt from one you have previously bought, but you can also buy a lactic ferment if you want to start from scratch.