Oil mills

Prepared by: Aloui Slah, Heritage Curator at the Ecomuseum of Arid Regions.

A traditional oil mill is generally set up in a cave or in adjacent excavations dug underground into rock or solid ground with irregular dimensions. This type of oil mill varies from one region to another; sometimes, several types can be found in the same region, such as in Beni Barka with the "Ouled Ouirene" mills (Plate 1) and the "Afine" family mill in the ancient village of Douiret (Plate 2). One can also find oil mills under shelters of regular dimensions, or semi-built structures like the Gasr Beni Ghdir mill, or entirely built ones like the "Lamloum" family mill in Tamezret. In the past, the setup of a traditional oil mill and the transportation of its equipment to mountain villages was an occasion for residents to celebrate a major event of mutual aid and collective work among men, accompanied by women, children, and a group of musicians, all working toward the completion of the task, which could take several days.

Space Organization of the Traditional Oil Mill

Usually, a traditional oil mill consists of two main areas:

1) The Crushing Area

2) The Pressing and Oil Extraction Area

The Crushing Area

Facing the entrance is the crushing area, which consists of a set of equipment where the two most important tools are:

• The Crushing Bed: A kind of circular platform built from masonry with a stone base called "meida" or "ferech." The dimensions of the bed vary from one mill to another, with a height between 70 cm and 1m, and a diameter of about two to two and a half meters, with a 15 cm rim around the edge of the platform, giving it the appearance of a shallow trough.

• The Millstone: A large cylindrical stone carved from rock called "kharza" or "T’ghaghet Inwandour," pierced in the center to house a traction axle; this is the "Assafadhoui" in Zeraoua or "Izenzagh" in Douiret.

The Crushing Millstone "Kherza"

By attaching the draft animal, which is usually a dromedary, the worker manages the crushing of the olives by gradually adding a quantity of two and a half "Ouiba" (a local unit of measurement for cereals and olives equivalent to 25-30 kg) into the crushing bed. With a continuous rotating movement of the stone driven by a blindfolded dromedary, the crushed olives are transformed into a paste.

At the end of the crushing process, the worker divides the paste into esparto grass baskets commonly known as "chamia" (plural "chouami"), with a volume of 4 to 5 kilograms in each, which are then taken to the pressing area.

2) The Pressing and Oil Extraction Area

The pressing area is located at the back of the cave on one side, or on both sides for mills equipped with two presses, also called "le Mgaam" by the highlanders of southeastern Tunisia.

Each press is composed of three main elements:

1. The Beam or "The Sari": A beam varying in length between 6 m and 10 m, generally made from the trunk of a wild olive tree or a palm tree. It is fixed on one side at the back of the cave and on the other to the counterweight.
   
   
   

   
2. The Counterweight or "The Mithguel": A large stone weighing about 1500 kg, used to exert pressure on the pressing beam. The large stone is equipped with two olive wood handles used to link the end of the beam through a roller polished by a rope.
   
   
   
   
3. "Elnend": The intermediate component, located in the middle of the pressing beam, where the mats filled with paste are stacked.
   
   
   

   During pressing, a mixture of oil and vegetable water (margine) flows toward two buried jars.
   
   

   Due to the difference in weight between the oil and the water, the water remains in the first pot and the oil floats to flow directly into the second one to be measured.
   
   

Bibliography:

- Louis A. Tunisia Du Sud Ksars et Villages des crêtes. National Center for Scientific Research. Paris 1975.

- Loussert Raymond and Brousse Gérard. Maisonneuve et Larose, Paris 1978.

 III: Lexicon of Local Terms

Component/Region	Zeraoua	Ghomrassen	Guermassa	Douiret	Beni Barka
Crushing Bed	Tassirt	elferch	elmeida	elferch	elferch
Millstone	T’ghaghet Inwandour	elkherza	errha	elhajra	elkherza
Traction Axle	Assafadhoui	lemdar	eljabbed	Izenzagh	elmagouied
Vertical Axle	Eyyoum	El gharssa	El gharssa	El gharssa	El gharssa
Olive Paste	Al’ossar	Al’ossar	Al’ossar	Al’ossar	Al’ossar
Pressing Mats	Tichoumay	chouami	chouami	chouami	chouami
The Beam ("Sari")	Ali gandouz	elmgam	essannoura	ennakhla	Ma’ssar
Counterweight	-	Mithguel	elmithguel	elmithguel	mithguel
Counterweight Pulley	Tajarraret	elmerwed	elgallab	elgattouss	elmerwed
Mat Stacking Area	Alma’ssar	elbend	-	Echam’a	-
Rotation Handles	-	M’fatih	M’fatih	Lemfatih	M’fatih
Rope	Izenzagh	lihbel	hbel	Errchaa	Rchaa
Oil Troughs	Issough	Khouabi	Khouabi	Khouabi	Khouabi
Warehouse	Issourèss	-	-	-	-
Oil	Oudi	Zit	Zit	Zit	Zit
Camel	Algham	Jmel	Jmel	Jmel	Jmel