The first organic producer of bufala (water-buffalo) milk, Tenuta Vannulo is a 10-minute drive from Paestum. It makes its mozzarella exclusively from buffalo milk, unlike most producers who combine it with cows' milk. Farm tours (also in English; cash payment only) are available and should be booked two to three days in advance. Visits proceed through the cheese-processing area, stable, agricultural museum and culminate in that all-important mozzarella tasting.
Tenuta Vannulo produces around 400kg of unpasteurised mozzarella di bufala per day, enough for several thousand caprese salads. It also makes wonderful ice cream, yogurt and budini (puddings). You can buy fresh mozzarella here, though demand is such that it generally runs out by early afternoon. Lunch is available with advance reservations.