The most important ingredient in cheese, is of course, the milk. Cheese can be made from just about any kind of milk including, cow, goat, sheep, mare and camels. It is the lucky home cheesemaker who even has access to fresh cow's milk, let alone the other exotic types. We will presume that the cheesemaker is limited to what can be purchased in the local supermarket. If fresh milk is available, consider yourself lucky and proceed in the same manner.
There are two characteristics of commercial milk that conspire to make life difficult for the cheesemaker. First of all, it is Pasteurized and the native flora and fauna are killed. This is not necessarily bad but simply puts a limit on the ultimate flavor potential of the cheese. However, this limit we can live with and as mentioned elsewhere, is a good compromise in favor of safety.
The really serious problem with store milk is that it is homogenized. This is a process that breaks up the fat globules to such a small size that they are forever in suspension and never again separate as in fresh milk. The bad news is that it does something else to the fat that interferes with making good quality cheese. The effect is to produce a wax-like texture that sticks to the teeth and hinders flavor development. The fix is to use the lowest fat milk available and replace the needed fat with whipping cream or butter. Although the whipping cream is also homogenized, the fat to casein ratio seems to prevent the fat from producing the texture defect.
I have experimented with various milks and have actually achieved the best results using powdered skim milk combined with whipping cream. Following the directions on the box and adding 1 pint cream per gallon of milk produces a cheese as good or better than by using fresh whole milk.
Some of the other variations I have used successfully are detailed below. My goal has been to be able to make cheese "out of a box" so to speak. All of these are based on a 4 gallon batch but can be scaled up or down.
Liquid plus Cream
3 pints whipping cream
2 tsp calcium chloride
Part Fresh/Part Dry
900 grams non fat dry powder
3 pints whipping cream
2 gallons 1% fresh milk
2 tsp calcium chloride
Dry and Cream
1260 grams non-fat milk powder
2 quarts whipping cream
2 tsp calcium chloride
Dry and Butter
1800 grams non-fat milk powder
1lb butter
2 tsp lecithin
2 tsp calcium chloride
Powdered Whole Milk
2080 grams Powdered Whole Milk
2 tsp calcium chloride
N.B. The dry and butter I extrapolated from a smaller batch in which I actually used an egg yolk to emulsify the butter in a quart of the milk. The lecithin works just as well and removes the potential risk of using raw egg.
Unfortunately, Powdered Whole Milk is not available locally for some reason that must have something to do with politics and the dairy lobby.
The only reasonable source I have found is Maple Island in Wisconsin http://www.maple-island.com/ I bought a 55 lb bag but it is also available in 5 lb cans.