Before this probiotic craze (or medical breakthrough), our families used to make yogurt at home. We would heat milk on medium flame, and stir and stir a starter yogurt (usually a teaspoon). Then after some time we would pour in plastic Tupperware, keep in separate place for 8 hours. Then yogurt would be ready and it would go in refrigerator. That's what I remember from those years ago. Does this yogurt automatically create probiotics. After all, the milk is fermented. Please advise.