Buffalo Mozzarella

Buffalo mozzarella is a fresh pasta filata cheese made exclusively from the milk of the Italian Mediterranean water buffalo. The protected name, Mozzarella di Bufala Campana, has held DOP status since 1996 and can only be used for cheese made in a defined area covering much of Caserta and Salerno provinces, parts of Naples and Benevento, a strip of southern Lazio and small zones in Puglia and Molise.

Buffalo milk behaves nothing like cow's milk. It carries around eight per cent fat against three and a half, nearly twice the calcium and, this is the visible part, no beta-carotene at all, because the buffalo converts it entirely into vitamin A. That is why the cheese is a flat, opaque white with none of the ivory tint of cow's-milk mozzarella.

Pasta filata describes a method, not an ingredient. The acidified curd is dropped into water at about ninety degrees and worked until it turns glossy and elastic, then mozzata, pinched off by hand between thumb and forefinger. That pinch gives the cheese its name.

A fresh one holds whey inside it. Cut into a good buffalo mozzarella and milky liquid should run out.

Lactic and slightly sour at the front, buttery in the middle, faintly grassy at the finish. There is a tang that cow's-milk mozzarella does not have, coming from the natural whey starter, and a mineral edge that reads almost as salt even in a lightly brined cheese.

The texture carries as much of the identity as the flavour. The outer skin is thin and gives way under slight pressure; inside, the paste separates into layers rather than behaving like a solid block, and it releases whey as you cut it. In the mouth it is springy for a moment and then melts.

Compared with the vacuum-packed mozzarella sold in blocks abroad, the difference is not subtlety versus richness. That product is a low-moisture cheese engineered to be grated and melted; this one is a fresh cheese engineered to be eaten within days, at room temperature, with nothing on it but olive oil.

Take it out of the fridge, or better never put it there, at least an hour before eating, and keep it in its whey until the last moment. Cold buffalo mozzarella is a waste of money: below ten degrees the fat crystallises and the paste turns grainy and dull. If it has been chilled, warming the packing liquid to about thirty degrees and letting the cheese sit in it for ten minutes recovers most of the texture.

Tear it rather than slicing it wherever the dish allows. The torn surface holds oil.

Raw is where it belongs: with new-pressed olive oil and black pepper, with anchovies, with confit cherry tomatoes, on bread alongside a sweet young prosciutto, or in a roll with hot bitter greens. Bitter vegetables suit it better than tomato, whose acidity simply adds to the cheese's own.

On pizza it needs managing. High water content means it weeps in the oven, so Neapolitan pizzaioli cut it into strips and squeeze it dry, or add it in the last moments. For a baked margherita, drier fiordilatte is often the better technical choice.

Skip the balsamic glaze. Sweet acidity flattens the lactic tang that you paid for.

The right place is out of the fridge, sitting in its own governing liquid at room temperature, if it is being eaten that day. Cold makes the fat set and the paste turns grainy and dull. When it does have to be kept, leave it in the liquid, on the least cold shelf, and take it out at least an hour before serving; better still, warm the liquid to around 30 C and let the ball sit in it for ten minutes, which brings most of the structure back.

The pack carries a date and that date belongs to the dairy, but the texture follows its own clock: from roughly the fourth day after production the acidity climbs and the whey turns cloudy. Keep the ball submerged once the bag is open, because one left out of its liquid dries at the surface, forms a skin and goes matt within hours. It does not freeze. The water held inside the leaves crystallises, and what thaws is a rubbery mass that behaves only in a hot dish. Abroad the ball has usually already flown, so the date on arrival is short.

Porcelain white, evenly so, with no yellow haloes. The surface is glossy and faintly wet and the skin is under a millimetre thick, continuous, giving under a finger without splitting. Cut one open and the paste shows overlapping leaves rather than a solid rubbery mass, and it should release plenty of milky whey: if nothing runs out, the ball is more than three or four days old, and if the liquid is clear rather than cloudy it was made from frozen curd. The bite resists briefly then gives way, slightly acidic, finishing like fresh butter, and it smells of milk and whey.

The label does the rest. Look for the DOP mark with the buffalo head and the dairy number. Mozzarella di latte di bufala without that mark is a legitimate cheese made outside the rules, often from frozen or imported milk. Be careful with packs that say only mozzarella and carry a photograph of a buffalo: if the ingredients list cow milk, it is fiordilatte with clever artwork. The low-moisture blocks sold abroad for pizza are a different product again, and the DOP ball costs several times as much.

In the UK, Ocado, Waitrose and Italian delicatessens carry DOP buffalo mozzarella flown in weekly, at roughly 18 to 30 pounds per kilo. Several British dairies (there are buffalo herds in Hampshire, Devon and Wales) sell a fresh, non-DOP buffalo mozzarella that is often in better condition simply because it has travelled a day rather than four.

In the US, Eataly, Whole Foods and Italian importers stock the imported DOP product at roughly 25 to 40 dollars a pound; domestic buffalo mozzarella from small dairies in California, Vermont and New York is cheaper and fresher.

Check two things on the tub: the DOP mark with the buffalo head and the dairy's identifying number, and the production date rather than the use-by date. Three days from production is the useful window; the printed expiry is more generous than the cheese is.

Be alert to labels that show a picture of a buffalo but list cow's milk in the ingredients. That is fiordilatte with clever photography, and it is legal.

Anything sold as buffalo mozzarella below about 10 euros or 12 dollars a kilo is almost certainly made from frozen curd or non-Italian milk.

The dairies themselves, in Caserta province and on the Sele plain south of Salerno. Many sell at the door and several have a small tasting room, and buffalo mozzarella eaten two hours after it was pinched off is a different food from the same cheese three days later. Not a subtlety: a different food.

Paestum, in Salerno province, hosts an annual festival dedicated to Mozzarella di Bufala Campana, with open dairies and tastings; Battipaglia, Eboli and Capaccio run related events at the same time of year.

Around Aversa and the lower Volturno, the tradition is older and the pieces smaller. Several historic dairies open for the morning stretching, which happens early, so arriving at seven is not excessive.

In Naples, the delicatessens of the Vomero and Chiaia take daily deliveries, and pizzerias that finish a pizza with raw buffalo mozzarella after it leaves the oven show exactly what the cooked version loses.

One practical warning for visitors: eat what you buy at the dairy on the day. It does not survive a suitcase, and travel damages it faster than time does.