Cow milk, goat milk or a combination of both may be used. Fresh milk is best (I'm talking FRESH here - like straight from the cow!) but store bought milk works fairly well. I have not tried the buttermilk version. There are numerous internet sources for cheese cultures, and they come in various forms (powder, frozen, etc). I have only used powder cultures from cheesemaking.com. Whatever form your culture is in, you should use the amount recommended for one gallon of milk, and follow any pre-cheesemaking instructions that come with it. This recipe was adapted from several sources and is designed for the beginning cheesemaker with limited access to specialty ingredients and equipment. Cheesemaking is a little tricky, as you are working with live cultures, as with sourdough bread, and a sensitive base - milk. It may take a few tries to get good results.