In the flatlands and hill towns of Puglia, late July and August mark the beginning of a domestic preservation cycle that has not changed substantially in over two centuries. Elongated tomatoes — primarily the San Marzano del Re and the local variety known as fiaschetto — are harvested at full maturity and processed within 24 hours before any fermentation can begin.
Selecting the right fruit
The choice of tomato variety matters more than most guides acknowledge. Puglian households favour tomatoes with thick walls, low water content, and firm flesh — qualities that allow the fruit to lose moisture evenly without going soft or mouldy during the outdoor drying phase. Round, pulpy varieties common in northern Italian cooking are considered unsuitable: their high moisture content drags the drying period to over a week and creates pockets of uneven dehydration.
Each tomato is washed under cold running water, then cut lengthwise — almost in two halves, but not fully separated so the fruit stays hinged. Seeds and excess liquid are squeezed out by hand. Some households in the Salento peninsula remove seeds entirely; others leave a few in place on the grounds that they contribute to flavour during the oil-curing stage.
The drying structure: cannizzi
The word cannizzi refers to the reed or wooden-slatted racks traditionally used for outdoor drying. These flat frames, typically one to two metres long, are elevated slightly above ground level on terracotta tiles or stone to allow airflow underneath. The tomatoes are arranged cut-side up, touching but not overlapping, and a thin layer of coarse sea salt is sprinkled across the surface. Salt accelerates evaporation and prevents surface mould during the first 24 hours.
Drying typically runs three to four full days under direct sun, with temperatures between 30°C and 38°C considered optimal. Each evening, the racks are moved indoors or covered with a cloth to prevent the night humidity from rehydrating the tomatoes. Families in coastal areas of Lecce province report that sea breezes significantly extend the drying window — the tomatoes dehydrate more slowly but develop a more pronounced flavour.
Judging doneness
The finished tomato should feel like fruit leather: pliable but not sticky, dark red or brick-red in colour, with a wrinkled skin. Moisture content at this stage sits around 30 percent of the original weight. A simple pressure test — pressing firmly between two fingers — should leave no visible moisture on the fingertip. Any residual internal softness means the tomato needs another day outdoors, or it risks introducing water into the preservation oil and shortening shelf life considerably.
Oil-curing: the sott'olio stage
Once dried, the tomatoes are packed into sterilised glass jars. The standard approach is to toss the dried tomatoes in a large bowl with extra virgin olive oil and — depending on regional practice — sliced garlic, chilli flakes, dried oregano, or a few capers. The oil coating ensures no air pocket forms between tomatoes as they are layered into the jar.
Jars are filled to within one to one-and-a-half centimetres of the rim. Additional oil is poured over the top to ensure the surface layer remains submerged — this is the point most commonly overlooked by casual preservers. Any tomato in contact with air will oxidise and develop off-flavours within two weeks. After sealing, jars rest in a cool, dark larder for a minimum of two months before first use, during which time the tomatoes soften slightly and the oil absorbs the herbs and the concentrated umami of the dried fruit.
Storage and use
Once a jar is opened, it should be kept at room temperature provided the remaining tomatoes stay submerged under oil — topping up the oil level as needed. Refrigeration causes the olive oil to solidify and is not recommended for traditional sott'olio preparations, as it alters the texture of the tomatoes and can introduce condensation when the jar is brought back to room temperature.
The Puglia Regional Authority lists pomodori secchi al sole as a protected traditional agri-food product (PAT), one of several hundred preservation methods formally documented in the region's cultural heritage records. The listing does not restrict production but confirms the method's authenticity as part of the regional food system.
Regional variation
The Murge plateau area, roughly between Bari and Taranto, produces a drier, more intense tomato than the coastal variant. Lower night temperatures mean the daily drying cycle is more pronounced, and many households in this area add a sprig of fresh basil to each jar rather than dried herbs, resulting in a noticeably different aroma profile after two months of curing. Along the Gargano promontory, the Pizzutello tomato — a smaller, elongated variety — is preferred for drying: its thick skin holds shape better over a long preservation period.