I only know how to make yogurt in large quantity. Here goes. Combine 1 gallon of whole milk with one gallon of half and half. It is important to use all of this fat because that is the bacteria can grow. Do Not try to use lowfat or skim milk.
Let the ingredients come to a boil; and let cool in room temperature atmosphere to about 120-130 degrees Fahrenheit. Then add a little bit of yogurt starter, or easier yet, about 6 tbsp of plain yogurt from the store. Cover the pot with a lid and towels on top and let it sit for about 6-8 hours in room temperature. Then refrigerate for 6 hours and enjoy!