At our dinner at Delfina earlier this week Antonio and I watched as the folks in the kitchen stretched mozzarella. Our waitress, Jeanine, explained that Delfina makes some of the mozzarella they use using cow's milk obtained from local dairies.
Of course, the most traditional mozzarella is made from the milk of the water buffalo, and, in Italy, comes from designated areas in the southern part of the country, much of it from the coastal areas in the region of Campania where the production apparently originated in the 12th century. The highest quality buffalo mozzarella bears a "Mozzarella di Bufala Campana" trademark, and an organization named Consorzio per la Tutela del Formaggio di Bufala Campana (The Consortium for the Protection of the Buffalo Cheese of Campania) oversees the promotion and marketing of mozzarella under that mark.
Almost all the mozzarella consumed here in the US is made from cow milk (sometimes referred to as "fior di latte mozzarella") and while some of it is quite good, according to the Consortia:
"Buffalo milk is not for drinking and is used exclusively for making mozzarella. Indeed, it is so nutritious and so rich in fat and cassein that it would be indigestible over the breakfast table, whereas it is the best for the cheese industry. Cow's-milk mozzarella is a ball of fresh cheese swimming in brine, pleasant as ice cream but absolutely tasteless."
So if one wants to avoid the "absolutely tasteless" alternative of cow's milk mozzarella one needs to find some real buffalo mozzarella. Of course the problem is that as a fresh cheese, mozzarella di bufala needs to be eaten as soon as possible (Italians will say ideally within hours of its production) and hence apart from the cost (and the dioxin scare of last March), several days of transit from Italy does not help its quality.
One ray of hope for those of us here in California is provided by a small California company named Bubalus Bubalis (the Latin name of the water buffalo) which for the last 10 years has been producing buffalo mozzarella at a plant in Gardena using a small herd of water buffalo raised on a farm in Bangor, about 70 miles north of Sacramento. Bubalus Bubalis' buffalo mozzarella can be found as some local cheese stores (including Cowgirl Creamery in the Ferry Building), and in fact Delfina offers it as an option (for a $2.25 surcharge) on its Margherita pizza.