History / Processing

Cold-pressed and cold-extracted olive oil

In both manufacturing processes, twigs and twigs are first mechanically removed from the olives in the oil mill (mostly by suction), washed and finally ground into an olive paste. Even with modern systems, this is usually done with stone presses, as stone only deforms minimally and does not heat up as quickly as metal.

During cold pressing, the olive oil is then pressed out of the olive paste with a hydraulic press using high pressure. Cold extraction is also a purely mechanical process, in which the oil is not extracted from the olive paste by pressure but in a centrifuge. These centrifuges work in a similar way to household juicers or the spin cycle of a washing machine, where the pulp is "extracted" in rapidly rotating drums. Cold extraction is the gentler and more modern process, because we know from physics lessons that pressure generates heat. The term first cold pressing is misleading, because nowadays olives are generally only pressed or extracted once. The machines used today are so powerful that a second pressing or extraction is completely unnecessary.

Even in ancient times, olive oil was extracted using simple screw presses that function like a large vice. Cold pressing or the more modern cold extraction are prerequisites for producing virgin (natural) olive oil.