Plain yogurt is the actually a type of frozen condition of the regular milk without any type of add on. Many people who cannot drink milk, because of protein allergy or lactose intolerance, can compensate their milk and calcium intake from plain yogurt. It is always suggested that because of the culturing process the yogurt is always more digestible than regular milk. Making plain yogurt at home is as easy as drinking a glass of milk after adding sugar. The main components needed to make plain yogurt at home are milk, dry milk powder and a little plain yogurt with active cultures.