Varieties
With so many different cheeses available, the question arises of why there are so many varieties of cheese?
To start, the milk can come from several different animals, although most cheese is made with cow's milk.
A lot of the flavor is derived from the various bacteria cultures added to milk before coagulation, as well as from the amount of salt added to the mixture and the time spent aging the cheese.
The texture is largely determined by how much of the whey is drained from the curds; less whey making for a drier cheese.
After the basic cheese is created, the process more greatly varies for different types of cheese.
The most basic, fresh cheese, is cheese that hasn't been aged. It's soft and has a mild flavor.
Pasta Filata is stretched or spun curds of cheese, such as mozzarella. These cheeses stretch out more when melted.
Soft Ripened cheeses are exposed to strands of mold, and aged for a short period of time. The mold starts from the outside, and makes a rind on the outside of the wheel, while leaving the inside soft. A good example is brie.
The texture is also somewhat determined by the amount of time spent aging. Cheeses categorized as semi-soft are aged for a somewhat short period of time, while semi-hard, the most popular kind of cheese, is aged for longer. Semi-hard cheeses get much of their flavor from aging as well as from their starter bacteria.
Washed rind cheese is well known for its stinkiness, a prime example being limburger. This type of cheese is washed routinely with seawater or alcoholic beverages. This was likely originally only intended to stop the growth of mold, but it also encourages the growth of the bacteria brevibacterium linens, which is responsible for the bad smell.
Blue cheese is similar to soft ripened cheese in the way that both are purposely introduced to mold. However, blue cheese has mold placed inside which is allowed to grow and create those distincive blue veins.
Finally, hard cheeses. These can be made by soaking the new wheels of cheese in salt water for several months, then aging said wheels for at least a year and a half. This results in very dry, low moisture cheeses, such as parmesan. Due to its hardness, this kind of cheese is often grated onto food instead of sliced.