The boast is easily forgiven: The Neapolitans are justly proud of their Mozzarella di Bufala Campana DOP, one of the most prized cheeses in Italy. Five producers in Naples and another 40 in nearby Caserta produce buffalo mozzarella conforming to the strict regulations set by its trademark DOP – Denominazione di Origine Protetta (“Protected Designation of Origin”).

The “DOP” pizza at Princi

When Neapolitans do order Mozzarella di Bufala Campana DOP on their pizza it’s usually set against fresh pomodorini (cherry tomatoes) rather a sauce made from tinned (canned) plum tomatoes. This pizza displays the classic Margherita’s Italian tricolore – basil for green, mozzarella for white, tomato for red – but is listed differently on menus. Often it’s designated as ‘Margherita Extra’, ‘Regina Margherita’ or simply ‘La Regina’ – “the Queen”. Sometimes it takes its name from its description, as in ‘Pizza con Mozzarella di Bufala e Pomodorini’. The Pizzeria Sorbillo in Naples employs the shorthand ‘DOC’, as in Denominazione di Origine Controllata, a distinction Mozzarella di Bufala Campana was granted in 1993. The mozza’s status was upgraded in 1996 from DOC to DOP but the name stuck. London’s Princi is more up-to-date, calling the same pizza ‘DOP’.

The straight dope on Margherita pizza in Naples is, with few exceptions, as follows:

If the mozzarella is from cow’s milk it goes on the pizza atop a layer of red sauce consisting of peeled plum tomatoes taken from a tin. If the mozzarella is from buffalo milk it is distributed over the dough in slices, cubes or torn pieces and then topped with slices of fresh tomatoes whenever good ones are in season and available. We’re talking little tomatoes, usually pomodorini but sometimes datterini (little dates) or fragolini (grapes).

Why fresh tomatoes? Most pizzaioli will tell you they provide buffalo mozzarella with greater stability. If the mozzarella di bufala is fresh and of good quality it is naturally juicy and, when subjected to the intense heat of a wood-fired oven, as molten as lava from Mount Vesuvius. If the flow of milky cheese juice runs over a bed of hot tomato sauce, rather than around fresh tomatoes, the pizza surface gets very runny. Quickly the mix of white and red liquids runneth over. As a pizza cheese mozzarella di bufala thrives on dry ground.

I_Borboni is a leading producer and champion of Asprinio di Aversa, an ancient white wine varietal with tree-hugging vines. The winery, which I visited in May, is situated in the town of Lusciano, about halfway between the two provinces where Asprinio is produced, Naples and Caserta. The appellation takes its last name from Aversa, the town in Caserta around which most of the vineyards are found. To grow Asprinio, I Borboni supports a traditionally Etruscan viticultural system known as vite maritata (“married vine”) by which the vines wrap around the tree trunks of poplar trees and climb to heights of 15 metres. This poses special challenges for the grape pickers, hence the made-to-measure scala napoletana.

The wine grower’s Neapolitan ladder is typically only 30 cm (about 1 ft) wide, with steps spaced 40-50 cm (15-20 inches) apart in accordance with the length of the climber’s lower leg. The spacing allows him to plant his foot on one rung and wedge his knee beneath the one directly above it, thereby stabilizing his position as he picks grapes, loads them into a basket and lowers it to the ground on a rope.

Can the origins of the rickety old ladder in Beuys’s sculpture be traced to the Asprinio vineyards of Naples and Caserta provinces? Two points count against the hypothesis:

1. Beuys’s ladder is too short to reach the heights of the poplar trees
2. The artist is said to have purchased the ladder from a landlord in Amalfi.

That said, maybe there are shorter ladders required for younger trees. Or maybe the artist used a segment cut from a longer ladder. The Amalfi Coast is only 23 km (about 37 miles) southeast of Naples – not very far for a ladder to travel. And Beuys did not name his sculpture Scala Amalfitana, did he? In the end, this may be one more tree that art historians will need to wrap their heads around and climb.