Glad somebody here is looking to make some cheese-
My
experience is that all hard cheeses, almost by definition, entail pasturization. It is thermophillic (heat loving) bacteria that make the cheese hard. All the raw cheeses I am familiar with, including cheddar, are mesophilic based. So I guess it depends on how you define 'hard cheese'.
Hard cheeses were traditionally made to best preserve the harvest for later use. In that context, skim milk is less prone to spoilage when made into cheese. Plus, you could make butter too. Just about all cheeses can be made with whole milk, but most thermophilic cheeses are going to be at least part skim. Then again, skim milk from a Jersey cow looks a lot like whole milk from a Holstein, so take that into consideration. Also, if you make cheese from whole Jersey milk, there is so much betterfat that some of it will actually get washed out in the whey.
The composition of the milk changes at least as much based on the stage of the cow's lactation as the season of the year. So if your milk is from a cow that calved in the springtime, as was traditional, then you are correct about the changing composition of the milk. But if the cow calved in a year round
dairy context, it is not as straighforward.
Lots of variables. What is the context of the animal you are getting your milk from? What is your objective for cheese type? More info and I can give even more info... Love talking milk!