Ceramic oil lamp
From the seventeenth century, the Gallipoli oil was considered the best in the Mediterranean area. Obtained from the pressing of olives, it was not used for food, but to light the houses, but, above all, the streets and squares. It was lampe oil.
Its price was beaten from Naples to London. Ships transported it from the port of Salento city to the main Italian and Northern European ports; from the latter it even reached the United States and the Russian steppes. It was used in the woolen shops of Great Britain and thanks to its purity it illuminated the icons venerated in the Orthodox churches of Moscow. Even the Winter Palace in Petersburg was lit up with Gallipoli oil that brought out the large halls full of mirrors and polychrome marbles. It seems that Tsarina Caterina had several times sent emissaries to Gallipoli to try to discover the secret hidden inside the hypogeal
These are not simply caves dug underground, but engineering works. Sometimes the caves were obtained from the transformation of Messapian granaries and crypts from the Byzantine era present in the subsoil of historic centers. But they were often dug under existing buildings. The giant wheels were lowered by hand. When these began to show cracks, they were destroyed and replaced: the roof vault was demolished and rebuilt after installing the new wheel.
Old hypogeal ipogeo
Oil mill wheel
The olives used to produce lampe oil were discharged directly into the mill from a hole in the vault. The decision to create underground oil mills allowed the product to be kept at a constant temperature of about 17 °.
The olives, kept in the ‘sciaghe’, did not risk moldy, which instead happened in the surface mills due to temperature changes (a problem for some neighboring countries). To produce a good lampe oil it was necessary to have intact olives, of good quality and not rotten.
The longer they remained in the sciagae, the higher their acidity and the more fat their oil was. The sciaghe worked as refrigerators where they remained for about 20-30 days. Later they were taken and crushed to bring out what was called the “mother”, a substance that was put in Calabrian presses: the olive paste was inserted inside several discs that acted as filters (called discoli).
As it was squeezed, the liquid that came out ended up in the “angel’s well”. It was not a pure oil, but a mixture of oil and settling water. The different density of the two elements favored their separation. The oil that remained on the surface was collected with a copper plate.
After the first pressing, the olive paste passed to the second and then to the third. The water that remained, then flowed into the “bilge well”. It was not pure water, but oily water, mixed with elements of oil processing. This was sent to Marseille for the production of the homonymous and famous local soap.
Production of Marseille soap with the settling water of the olives.
From the tanks, the oil was then taken to the Royal Loading Piles which were located near the fish market. Graduated batteries that were filled with oil waiting to be loaded on ships and sold all over the world.
Working in the mills was a seasonal job, from October to March, well paid but exhausting: the humid air, often poor in oxygen and full of germs and bacteria (men and animals worked, ate and slept inside the caves, almost never going out) led to frequent cases of fatal diseases.
The lamp oil trade brought benefits to the entire city economy. The Aragonese changed its management every year to allow many inhabitants of Gallipoli to improve their finances. The oil mills were gathered in brotherhoods that often invested the revenues in public works and churches that still contribute to spreading the architectural value of the historic city of Gallipoli.
The discovery of electricity marks the decline of this activity: many of the oil mills were closed and used as warehouses or landfills. Some of these objects have been transformed into museums, intended to spread a slice of Mediterranean history.