Sheep's milk can (and is) made into every style of cheese under the sun. But beyond versatility, sheep cheese has several particular qualities worth learning about as you navigate the cheese case.
Left to their own natural birthing cycles, all farm animal milk is seasonal, but this is especially true for sheep. They have the shortest lactation cycle, meaning they produce milk for only five to seven months after giving birth. Daylight impacts their milk production, and as the days get shorter in the fall and winter, the animals' milk production shuts down. In order to produce milk year-round, cheesemakers have to maintain two separate flocks and use light exposure to offset the natural proclivity to cease lactation in colder months. Sheep also produce less milk than cows or goats (half a gallon a day versus eight gallons a day from the average Holstein cow). Point being: you don't get much milk for much time from a sheep.
What you do get is milk that is considerably richer than cow or goat milk: it has nearly double the fat and protein of cow's milk, for example. That incredibly rich milk impacts the final cheese; even hard, aged styles have a weight and density in the mouth thanks to this super milk.
But if you're wondering why sheep milk cheese is rare among American makers, that scarcity is why. It's hard to make to make the cheese profitable.
I asked several American sheep cheese producers about the challenges they face and how they solve them. Most American sheep cheese makers also produce cow or goat cheeses to round out limited production (not to mention wool and meat). And some makers say that European sheep genetics are superior to American breeds, but it's almost impossible to obtain European breeding stock in U.S.
Europe has sheep to thank for some of its most iconic cheeses: Italian Pecorino, Greek feta, Spanish Manchego, Roquefort, and French Pyrenees, to name a few. At both a national and regional level, Europeans have a vested interest in preserving and fostering traditional agriculture, and nearly all European makers benefit from country and E.U. subsidies. But that's not so in the U.S., where sheep cheese gets little government support.
To delve into these cheeses: "Pecorino" refers simply to the presence of sheep ("pecora") milk. Pecorino is made in every region of Italy, sometimes moist, mild, and young and other times cut, pressed, and heavily salted, as in the amazingly intense Pecorino Romano. It can be laced with truffle, pepper, or saffron, and eaten as a table cheese or reserved exclusively for grating.
I'm convinced Manchego succeeded as the cheese that put Spain on the map because it showcases the best of what sheep cheese can be. (Similarly I'm convinced that Ossau Iraty, from the French Pyrenees, could be the next cheese darling, as it shares Manchego's likeability with a more elegant, smooth-fatty texture).
Both cheeses are cut and pressed during cheesemaking and then aged for some three to twelve months. They capture the familiar-cheesey-yet-different quality that makes sheep milk so approachable. Often reminiscent of boxed macaroni and cheese (in the best ways), macadamia nuts, or something butterscotchy, these are easy eating cheeses. That fat/protein density makes them well suited to tannic or acidic wines. They're new, but compulsively edible.
When sheep cheese gets weird, the quality that shines through (often in aroma more than flavor) is lanolin. That's the oil in sheep wool, and it's the dank smell of wet wool socks or, more intensely, the flavor of rare lamb chops close to the bone. Cheese folk lovingly refer to these qualities as "rustic," but new cheese-eaters often find them overly animal or barnyardy. I find them more often in soft Brie-type sheep cheeses like the rusty red Brebisrousse d'Argental.
A special and rare cheese style to seek out is the exclusively sheep milk, thistle-coagulated cheeses of southern Spain and Portugal. La Serena, Torta del Casar, and Zimbro all come in rounds designed to be served whole. The tops are sliced off to reveal a pudding-like mass designed to be scooped directly from the rind. Wobbly and gelatinous with intensely sour, vegetal, "green" flavors, they are worth seeking out if for no other reason than they're unlike any other cheese in the world. Sheep cheese is definitely approachable, but it also knows how to bring the funk.