The Appearance and Spreading of the Presses

The simplest system to squeeze the olives is to put a stone on the pulp until the pressure gives us the prospective result. The first machine though, was invented when someone had the idea to hang a stone from a crowbar. During the archeological excavations, there is abundance of stones – the basis for crushing – with a groove for the access of the sacks with the pulp, as it happens nowadays in Province.According to the way of pressing the presses are assorted into the following (Parain, 1990):

Presses with chock

All these methods had already been familiar in the 1st century BC. During the Roman Times they were spread in all the Mediterranean areas as a result of the increase on demand and of the oil production (Mattingly, 1988. Hitchner, 1993).

There were, though, some variations from area to area. So one of the main problems these machines presented was the risk of tearing due to pressure. To avoid that risk, each area created its own way of angling the crowbar.

In Italy for instance, the wooden pales – the arbores of Latins- were inserted deeply on the walls, while in Cyprus, in Dalmatia and in north-east Africa they preferred the use of perforated monoliths. Occasionally the same crowbar was hooked on the wall, which was a thing that inhibited the mobility in shifting. With stone bases for crushing instead from wood the stability was bigger. For that reason this system was used in Lebanon and in Judea (Callot, 1984. Eitam, 1987. Kloner Saruiv, 1993).

The press with a wedge is an evidence on murals of Pompeii, where they possibly used it for the oil production which was intended for perfume making (Mattingly, 1990).

As far as the press with crowbar is concerned, it sustained one last change when the screw bar appeared. The screw bar in combination with weights expedited the laborer's job and simultaneously it raised the safety degree of the press. This press, which was widespread at the end of the Roman domination, was greatly used during the Middle Age. Later it was improved more by the addition of spindles and was named according to the areas (Frankel, 1993. Amouretti, Comet, Paillet, 1984).

Last, the presses with screw bar appeared just before the end of the 1st century BC. Although they allowed an instant control of the pressed oil, they did not have great stability and they demanded the cooperation of more people. They were wholly made of wood and they did not leave many traces. Their types were two: one –column or two – column- and of course their spreading was bigger than it is believed.

In conclusion, we have to say that all the technical alterations were accomplished during Ancient Times. During the Middle Age and in the Early Age only some specific elements were improved. For instance, Trapetum disappeared, for the benefit of bigger size millstone, while the cylinders remained. Also the productivity of the press with crowbar was raised and efforts were made in order to improve the size of the spindles.

The Separation of Oil from Water

As oil is lighter than water, it floats and it can be collected by hand or by a swallow spoon. For that reason all the systems of separation used water regardless of the kind of pots: big earthenware jars (the Greek earthenware jars, the Roman dolia) or built receiving basins (Brun, 1993). Undoubtedly the most beautiful pots are the expansive effusive basins of North Africa (Camps, see below).

As it seems only later in the 16th century AC, the exploitation of olive cake started, for the extraction through the oppression of the remained oil from the pulp, even though this oil is of lower quality.