This explains "first cold press" olive oil. This is the most paleo. Don.

Newsgroups: alt.support.diet.low-carb,alt.support.diet
Subject: Re: Neanderthin
From: "Opinicus" <[log in to unmask]>
Date: Tue, 19 May 1998 07:47:06 +0300

I spent a year in Ayvalik, an olive-growing center on the
northern Aegean in Turkey. In December and January huge baskets
of ripened olives are brought in from the groves to the
processing plant and then hosed down in cold water to get the
mud and other gunk off them (some of it anyhow). The olives are
then placed in a big cylindrical tank. The weight of the mass
crushes the olives near the bottom and the first "cold press"
oil is drawn off. This is the most prized and valuable oil. Next
pressure is applied from the top compressing the mass to a large
fraction of its original size. This oil is second quality, but
still very good. (In Turkish it's called "naturel" grade.) Next
they really squeeze the HELL out of what's left, compressing the
mass to a small fraction of its original size, and draw that oil
off. This is the stuff that goes to the refinery because it's so
highly acidic. It's sometimes blended with "good" oil to make it
more palatable. (Sometimes it's used to adulturate the better
oils to make them less expensive.) The pressure causes the mass
to heat up, which is why the first-quality oil is called
"cold-press".

The leftovers--flattened cakes of olive skins and pits--are used
for animal feed.

I should add that NOTHING from the olive-tree is wasted. For
example the water used to wash the olives and oil at various
stages is centrifuged to separate the water from any oil that
might be contained in it. That oil is drawn off and used to make
soap.

A side note to a poster who asked about processing olives. As
someone else said, ripe olives off a tree can be eaten; they
just don't taste very good. The olives that MUST be processed
are the green (unripe) ones. The processing involves the use of
lye and is not for the faint-hearted.

Bob
Munching on a couple green olives in Istanbul