Practical
advice
Olive
oil grading follows international quality standards according to the
method of production, the level of acidity and basic organic characteristics.
Special testers check the taste and smell of an oil. Taste and smell,
in connection with colour, are the three areas checked by international
testers in assessing the quality level of a product. Fluidity and
a harmonious – balanced relationship between the characteristics
of the oil, are used to form a final evaluation.
Colour
Colour
does not always prove the quality of an oil. A good oil can be from
green to golden yellow. It can even seem cloudy if it has not settled
yet. As colour is not a sure sign of quality, experts test olive oil
in dark blue and not transparent glasses. The colour of the product
depends on the main substances of the olive fruit that the oil has
been made from. If chlorophyll is the main factor, then the oil will
lean more towards the colour green. If carotene is the main substance,
then the oil will be more golden yellow. Olives which are gathered
at the beginning of the harvesting period, usually produce oil of
a greener colour, due to the chlorophyll they contain.
Taste and smell
Olive
oil reminiscent of the scent either of fruit or of oil fresh from
pressing is believed to be excellent. This is the same with wine as
testers try to pinpoint pleasant smells which remind them of other
products, such as fruit, like apples or nuts, etc.
A bitter
or slightly bitter taste shows that the olives used were not ripe
when picked. A pleasant smell and taste can also be put down to the
area in which the olives grew and the way they were cultivated. A
fruit taste comes from ripe olives which have balanced characteristics.
Olive oil with an unpleasant smell and taste is better avoided. Smelling
soil or mould down-grade a product. It can be seen then that experience
is needed for someone to safely assess an oil.
Acidity
The degree
of acidity in olive oil indicates the oleic acid content. It is believed
to be edible, according to the International Olive Oil Council, when
the acidity does not exceed 3.3 degrees (content of oleic acid 3.3%).
In reality, olive oil which has an acidity level of no more than one
is much better. You should always read the label on an olive oil bottle
to see the degree of the acidity. In Greece, there is excellent olive
oil with acidity less than 0.5 degrees! The degree of acidity greatly
affects the taste.
Oxidization
Oxidization
(rancidity) is one of the most important causes of spoiling olive
oil. Conditions of storage (light, oxygen etc) help oxidization. This
is easily spotted by a tester without scientific tests, as the taste
is badly affected by oxidization. Olive oil producers can distinguish
good quality from rancid oil, after years of experience. As they say,
“the oil got rancid and smells like soil”. On Crete, they
identify the smell of rancid olive oil with the smell of soil. Similarly,
at Kalavryta of the Peloponnese they say “the oil is not good
because it nips the tongue.”
Oxidization
reduces or destroys the basic components in olive oil, especially
those which are unique to this produce, in contrast to all the other
fat substances. It can destroy the fat-soluble vitamins or the fatty
acids such as linoleic and linolenic but it can also produce substances
which are dangerous for the human body.