Good cheese starts with good milk. To really understand cheese you have to start at the milk source.
Where Does Milk Come From?
You already know that goats, sheep, cows, water buffalo and a whole variety of other mammals produce milk. But it's a little bit more complicated than just that - milk doesn't just flow forth 24/7/365. At its most fundamental level, milk is a food source for an animal's offspring. Female animals, including humans, must reproduce in order for their bodies to produce milk.
In order to talk about where milk comes from we also have to delve briefly into arcane topics like breeding and lactation cycles. Let's start here: in the natural scheme of things, an animal's milk production is seasonal. What we now think of as dairy animals - cows, sheep, goats - typically give birth in the late winter or early spring and produce milk for their young for a period of time which varies greatly by breed and species, but is generally in the neighborhood of 6-8 months. Milk production normally (i.e. without human intervention) wanes in the fall and winter months, then ceases altogether. An animal would then need to reproduce again the next spring in order to produce milk for new offspring, and so the cycle would continue.
Over the centuries, milk became something more than simply a food source for a given animal's offspring - humans started to use milk as a food source for themselves. Jump forward several thousand years to today's modern consumer, who expects milk on store shelves at all times. And so developed the modern system of dairy animal management that ensures the availability of a year round milk supply. A huge part of the modern dairy farmer's job is managing a herd of cows such that there are always a few giving milk at any given time, all throughout the year. They accomplish this feat by breeding cows in groups at defined intervals such that the overall result is essentially a constant stream of babies, and thus a continuous flow of milk, 365 days a year.
That's how things work in the (cow) dairy industry, but it's not how all farms operate. In particular, some small farmstead cheesemakers manage their milk supply more seasonally; they will breed their animals - goats, cows or sheep - so that babies start coming in the spring, ensuring a generally steady milk supply until fall. The winter months become a welcome period of rest for animals and cheesemakers. That being said, this leaves a period of time during the winter when no cheese is being made, with obvious effects on a cheesemaker's income.
I should also mention that while goats in general are adaptable to a year round milking schedule, sheep as a species generally don't adapt as well to year-round breeding. Thus you'll find that most sheep dairies - and sheep's milk cheesemakers - operate on a seasonal basis.
How are Animals Milked?
Some small dairies and farmstead cheesemakers still milk their animals by hand, the old fashioned labor intensive way. One of the few cheesemakers that I know of that still do things this way are Rick and Lora Lea Misterly at Quillisascut in Northeastern Washington. But hand milking isn't practical on a large scale with dozens or hundreds of animals, so most farmers milk their animals using automated equipment (see photo at left of a dairy sheep being milked). Automated milking, as the name implies, does it all for you! Nozzles are attached by the force of suction to an animal's udder. The suction then forces the milk out of the udder and then siphons it into a tank or other collection vessel. Milk from the entire herd is usually pooled together, and then the milk may either be sold to a dairy processor, or used to make dairy products like cheese.
Where Do Cheesemakers Get Milk?
It's a given that cheesemakers must have milk to make cheese, but not all cheesemakers own animals. This means a cheesemaker has essentially one of two options....she can purchase milk, which comes with associated issues like finding a milk supply, transporting milk from one place to their cheesemaking facility, and so on. A cheesemaker may also buy land or may already operate a farm with dairy animals which produce milk, and that milk can then be used in cheesemaking. This has its own set of associated issues as well, like running a farm at the same time you're making cheese. This second type of cheesemaker is termed a farmstead cheesemaker - a cheesemaker who makes cheese from the milk of animals living where the cheese is also made.
What's in Milk?
Milk is composed of a number of different components - water, lactose, butterfat and proteins - but it's the butterfat and proteins that are important for making cheese. Butterfat and protein content in milk varies by species and by breeds within species: take cows, for example. Jersey cows give milk that is higher in butterfat than Holstein cows, and other cow breeds like Guernsey or Milking Shorthorn have different variations on levels of proteins and fats in their milk. Butterfat and other milk components will also vary as any animal goes through its lactation cycle; butterfat levels will typically be higher in the latter stages of an animal's lactation cycle, as milk volume is beginning to decrease.
Milk composition varies across species. For example, sheep's milk and water buffalo milk are much higher in butterfat - 8% or more - than cow and goat's milk, which run in the 3-4% range. Higher butterfat milk makes cheese that is richer, with a distinct tanginess and complexity that's different than what you'll typically find in a cheese made with lower butterfat milk. Taste and compare a cow's milk and sheep's milk cheese of relatively the same age, you'll notice the difference right away. (Try, for example, Ossau-Iraty up against Comte, or Black Sheep Creamery Mopsy's Best next to Oregon Gourmet Sublimity).
Milk composition and quality can be affected by a whole host of environmental factors as well - perhaps most importantly, what the animal eats. Thus cheesemakers are constantly concerned about the quality of pasture, forage, hay and/or grain that goes into the mouths - and thus into the milk - of the animals that give the milk that goes into their cheese. If you are ever able to taste the same farmstead cheese made at different times of the year, you will notice the effects of pasture grazing in the cheese during the summer months. This is why some cheesemakers will say that cheese made from summer milk is the best cheese of the year.
So without getting too heavily into the science, I hope you can see where this is going - cheesemakers must pay close attention to milk chemistry throughout the year in order to ensure the quality and consistency of the cheese that they make. No mean feat.
Bottom Line: Good Cheese is a Function of Good Milk
As you can see, cheesemakers must put an incredible amount of thought and analysis into cheese on the front end, before the milk is ever turned into cheese curds and becomes the cheese that reaches you, the hungry consumer. Whether a cheesemaker purchases milk, or keeps animals, the considerations are essentially the same (though the level of control may not be) and have a tremendous effect on the end product.....the cheese.
******** Resources ******** Cow Breeds
For more on the cultural and culinary history of milk, see Anne Mendelson's fascinating book Milk: The Surprising Story of Milk Through the Ages
For more specifics on the science of milk components and their effect on cheese production see the University of Guelph website (a great resource in general) here.
Next: How Cheese is Made Part II - From Milk to Curd