The queue at Pizzeria Gino Sorbillo is five deep and as long as a Neapolitan summer evening when we turn up unfashionably early to avoid the crush. Those who fail to grasp the drill - gently insinuate your way to the front, give the man with the clipboard your name, then never let him leave your sight - could loiter on the flagstones of Via dei Tribunali for a long time. Somehow, though, in the haphazard way of Italy, the system works.
When in Naples thoughts inevitably turn to pizza. The evening crowd outside our pizzeria threatens to block this narrow artery of Centro Storico, the city's moody, labyrinthine old quarter. Along with L'Antica Pizzeria da Michele, Pizzeria Di Matteo and Pizzeria Starita, Gino Sorbillo is among the city's most celebrated pizzerie, the handiwork of the eponymous Gino, scion of generations of distinguished pizzaioli.
To kill time we duck next door to Vinorum Historia Enoteca and order brimming plastic cups of local aglianico, a rustic and savoury red, and falanghina, a lively Campanian white wine. Forty minutes later we're ushered past Pizzeria Gino Sorbillo's two shiny wood-fired ovens and upstairs to a marble-topped table in the simple dining room.
Crowds outside Pizzeria Gino Sorbillo.
Naples, founded as the Greek settlement of Parthenope around the 9th century BC, is home to what are traditionally acknowledged to be the world's best pizze. Its oldest pizzeria, Antica Pizzeria Port'Alba, opened as a stall in 1738 and still operates from a modest shopfront. When we show some interest, craning necks to admire the handsome wood-fired oven, we're piloted inside for a better look. We leave clutching a slice of pizza a portafoglio - neatly folded in four like a wallet and stuffed in a brown paper bag - for just two euro.
Later at Gino Sorbillo, we order pizza Margherita, the city's famous red, white and green pie created for Queen Margherita in 1889, and still considered the best means to judge a pizzaiolo's deftness. Pizza bases here are made with a sourdough starter. The base is deeply flavoursome, puffy-edged and lightly freckled, and topped with a slick of crushed organic Italian tomatoes and molten discs of fior di latte misto, a mozzarella made with cow's milk and buffalo milk from the nearby Matese region. There's a single fresh basil leaf at the centre. It's hard to find bad pizza in Naples, but the balance at Gino Sorbillo between the chewy, almost nutty-tasting base, the creamy cheese and the tart tomato sauce is faultless.
A cornerstone of great Neapolitan pizza is great tomatoes, although the fruit is a relative newcomer to the city. It was a Neapolitan cook named Francesco Gaudenzio who first suggested crushing and cooking the saffron-coloured pomodoro ("golden apple") in 1705. A little over a century later another Neapolitan, Don Ippolito Cavalcanti, suggested using the sauce to dress pasta, ensuring its enduring popularity. Tomatoes went on to star in all Campania's finest dishes, from spaghetti Napoletana and parmigiana di melanzane to the olive-studded chiummenzana sauce from nearby Capri and, of course, on many of the region's best-loved pizze.
Tomatoes at the Calispa plant.
I've come to southern Italy in search of the perfect tomato. My guide is Giovanni De Angelis, whose career has been pretty much dedicated to the topic.
"Naples is the capital city of the tomato," says De Angelis, a director of L'Associazione Nazionale Industriali Conserve Alimentari Vegetali, which represents the country's fruit and vegetable preserving industry. It's a big business, with an annual turnover of about €6.1 billion, which includes the nation's €3.1 billion canned tomato output. Sixty per cent of Italy's total tomato production is exported; about 40 per cent of Australia's canned tomatoes come from Italy.
For Neapolitans, the humble tomato represents much more than a cooking staple. "In each of our cans there's a strip of our land. Just as Capri represents the best of Mediterranean style and beauty, Naples represents tomatoes," says De Angelis. "There's an important bond between the country and the produce - the tomato business has a kind of soul."
Italy's first tomato-canning plant was established in Campania. This preservation method enabled the perishable produce to be sent worldwide as pelati, or peeled tomatoes, and paste, called conserva. The elongated Roma variety, which is peeled and canned whole, is grown exclusively in the south. And it's here our search for perfect pelati begins.
Caprese salad at Hotel Voce del Mare.
From Naples we drive east, past the sullen bulk of Mount Vesuvius and on through mountains and fertile plateaux to the market town of Foggia in neighbouring Puglia - where most of the nation's Romas now grow in vast, easy-to-harvest fields. Instead of climbing vertically on stakes, like the premium San Marzano variety grown only in the volcanic soils of the Agro Nocerino Sarnese region, these Roma vines hug the soil, red fruit shining like baubles in the dirt. It will be at least four years before tomatoes are grown here again. After each harvest the ground is prepared for wheat - a pleasing synergy between the crops that create pasta and pizze. In another neat twist, at the fourth-generation family-owned Pomodoro Mutti factory in Oliveto Citra, rejected green tomatoes are fed to the buffalo that produce the milk for mozzarella.
The bittersweet heirloom San Marzano is considered the monarch of tomatoes and is the only fruit used for "verace pizza Napoletana", or true Neapolitan pizza. The tree-lined town of Castel San Giorgio in the province of Salerno is home to tomato giant Calispa, owned by the deep-pocketed Di Leo family and one of the few companies that owns its own San Marzano fields.
Founded in 1966 by Attilio Avino, Calispa deals in all things tomato, including the premium Nobile brand, which includes canned peeled and organic tomatoes, baby Roma or date tomatoes called datterini, the newer Marzanini tomato - a baby version of the famous slender, firm-fleshed plum-style San Marzano - and, naturally, the prized San Marzano.
View of Vietri sul Mare from Hotel Voce del Mare.
The Di Leo family also owns the Hotel Voce del Mare, about 40 minutes' drive south of Naples in the hilltop village of Vietri sul Mare, the gateway to the Amalfi Coast. Here, in an all-white dining room popular with local brides, we try both fresh and preserved San Marzano tomatoes. The six-course tasting menu by head chef Gianpaolo Zoccola is dedicated to tomatoes, which feature in a Caprese salad with layers of oregano-spiked fresh San Marzano tomatoes, and paccheri al Marzanino, the al dente pasta tubes dressed in a sweet Marzanino sauce with fresh basil and creamy burrata.
The dishes are paired with a spicy 2011 Taurasi Alta Valle DOCG made from the local aglianico grape, and a bottle of pale golden 2015 Feudi di San Gregorio Serrocielo Falanghina. Salt-cod dumplings the size of snooker balls arrive in a tart San Marzano sauce, a scatter of sourdough crumbs and a swipe of squid ink on the plate the only adornment. A crisp-skinned fillet of local amberjack is presented simply in a vivid datterini sauce. And a scoop of tomato ice-cream reminds us that the tomato is first and foremost a fruit, tasting almost tropical - here atop a yolk-coloured slab of rum-soaked baba.
San Marzano production, from seeds to labelling, is limited to about 200 hectares a year, a fraction of the 80,000 hectares used to grow Italy's entire tomato crop. Although the industry is heavily regulated, the occasional tin of fake product makes its way onto supermarket shelves. Real San Marzanos, says Calispa president Gianluigi Di Leo, are always hand-picked and sold whole. "The Roma has either two or three chambers, but San Marzano tomatoes have two," he says. "The San Marzano has visible venatura [veining] - white-yellow striations. The San Marzano also has lighter juice than the Roma."
Rum baba with tomato ice-cream at Hotel Voce del Mare, Amalfi Coast.
Working on the premise that too much is never enough, we take a fast ferry to Capri the next day to try a Caprese salad on the island where it was created, fortifying ourselves for the 50-kilometre boat ride with espressi from a café at Molo Beverello quay in Naples. We take the funicular for a spectacular four-minute ascent from the Marina Grande to Piazza Umberto 1, better known as La Piazzetta, in the town centre, climbing past the island's yellow, pink and white buildings, many trained with purple and pink bougainvillea vines.
After a trawl of the winding laneways and their designer shops, a fresh lemon juice on the terrace of the Grand Hotel Quisisana affords stellar people-watching opportunities. It was here at the Quisisana, legend has it, that the Caprese salad was devised during the interwar years. "It's not one of the most reliable stories," admits De Angelis, laughing. "But it is said the first Caprese salad was prepared in the 1920s for a Futurist who wanted to go against tradition. Instead of using tomato with pasta he wanted to have something from the future. So the chef put basil, tomato and mozzarella together to represent the colours of the Italian flag - and the Caprese was born." It's said the salad's fame spread after it was served to King Farouk I of Egypt when he visited the island in the 1950s.
On the boutique-lined Via Camerelle, a short stroll from the Grand Hotel Quisisana, we sit at one of the white-clothed tables at Le Camerelle Ristorante. Its version of the Caprese is stacked vertically, with layers of oxheart tomato and buffalo mozzarella instead of the original fior di latte, drizzled with oil and garnished with basil. It sits on a quartet of what look like deep-red piennolo tomatoes, known for their distinctive nipple at the blossom end.
Teamed with glasses of chilled falanghina from the Sannio Hills, it's certainly a memorable take on the dish. The restaurant's Neapolitan calamarata, the pasta mimicking rings of squid, served with a rich tomato-octopus ragù studded with black olives is another standout.
Fresh produce at La Pignasecca, the oldest street market in Naples.
Back in Naples, we walk the ragged length of La Pignasecca, the city's oldest street market. Lining the street are old-style vendors - tripe sellers, specialist grocers and pastry shops - so we have a chance to assess the region's best produce in a single location.
There are bowls full of silver anchovies and pink-tinged baby red mullet, crates stuffed with baby octopus looking like cacti, and impressive shiny beltfish - so long and narrow they could be mistaken for eels. Everywhere are tomatoes: golden explosions of spunzillo, clusters of dark red piennolo from Nocera, and knobbly oxhearts streaked with green and red often used for Caprese salad. Our thoughts turn again to pizza.
At Pizzeria Starita on Via Materdei, Antonio Starita has made a name for himself with his Montanara Starita - a deep-fried pizza base topped with smoked provola cheese from Agerola, and pecorino, the whole thing anchored by a vibrant tomato sauce.
Celebrated pizzaiolo Antonio Starita.
Starita is a third-generation pizzeria owner who runs a shop in New York called Don Antonio by Starita. So what makes for the perfect pizza? "San Marzano has a slightly sour flavour that is perfect for pizza, and if you make it with fior di latte made from milk from the Sorrento coast it helps the pizzaiolo even more to get the right balance between the San Marzano tomato and the base," says Starita. "For pizza, tomatoes shouldn't be too sweet - they should have a lightly sour taste."
In life, and in pizza, the answer lies in balance. And in finding the perfect tomato.