We just got finished discussing the history of olive oil, from biblical times through Ancient
Greece and Ancient Rome, all the way to modern times. So let’s now get to the production of
this amazing product. As we may be aware, a lot of olive oil is quite expensive, but as
we will see shortly, for a genuine product this price is justified, as it’s a delicate process.
The main phases of olive oil production are: raccolta, or harvesting, lavaggio, or washing,
frangitura, or grinding, gramolatura, or malaxing, estrazione, or extraction, separazione,
or separation, and finally imbottigliamento, or bottling. Let’s go through these one at a time.
Raccolta. This is the most delicate and important phase for a good olive oil,
and in Italy this is all done by hand. Olives are fragile and they bruise easily. Therefore
they cannot touch the ground when they are harvested. The trees are shaken gently,
and umbrella-like nets are placed underneath, in order to avoid stressing the olives. Any lesion in
the olives would increase the acidity in the oil and this would translate into an inferior quality.
At this point the olives are placed in perforated crates in order to allow the olives to breath.
This is apparently very important. Burlaps should never be used as they would warm up the olives
and initiate a process of fermentation. The best time for this phase is mid-October to December.
Lavaggio. The olives are brought to the Frantoio, or olive press, the same day that
they are harvested. Here the olives are carried by a conveyor belt to a tank where they are separated
from leaves, twigs, and other debris by means of a powerful vacuum. Only now do the olives get
washed and rinsed again in clean water. At this point the olives still have their pits.
Frangitura. After being washed, the olives are crushed into a coarse paste
made of solids, pulp, skin, pits, and some oil. The oldest method is by stone mills,
but today more modern machines may be used.
Gramolatura. The next phase is a process of slow and continuous kneading, called gramolazione.
This is a very important step which allows the separation of oil and water from solids. Small oil
droplets will combine with others in order to form larger ones. Normally a mixer is horizontal with
spiraled mixing blades. For the best quality of oil, this process should be done with temperatures
below 27oC, or around 80 Fahrenheit. If heat is used the oil will be an inferior product.
Estrazione. This is the step yielding the product we all know and love.
It used to be made with presses, alternating layers of olive paste with filtering discs,
hence the expression cold press or first press. Today it’s often made by centrifugation.
Separazione. At the end of this extraction, the liquids which are still containing some water,
will be easily separated from the oil since oil is lighter than water.
The best oil is done naturally. Enzymes, steam, hexane, and other solvents could be used as
well as bleaching the oil to reduce chlorophyll, carotenoids, residual fatty acids, and pesticides.
It goes without saying that all these steps are only used for lower quality oil.
Imbottigliamento. At the end of the entire process the olive oil is finally bottled.
The best material for this is glass, usually dark glass, or non-reactive metal cans,
in order to protect the oil from light and avoid oxidation. These are immediately hermetically
sealed in order to avoid any alteration of the precious product. Usually this phase happens in
the middle of October until the end of November, approximately two months after harvesting.
Now that we’ve made our way through the production process, let’s take a look at the three types
of oil that are available for purchase. First up, extra vergine DOP is the best of the best.
It doesn’t utilize chemical extraction, and it has the lowest acidity,
less than 0.8%. This product is specifically for direct consumption. Vergine utilizes
mechanical extraction limited to 2%. This is still a good alimentary product.
Olio di sansa is the lowest grade of oil, obtained by chemical extraction.
It is still edible and typically used for frying, but it is not the best or the healthiest oil.
Lampante has the highest acidity, which makes it unsuitable for consumption.
This is used only for lamps and torches. Now when you go to buy your olive oil,
if you’re looking to get the best, pay attention to a few details. Good olive oil will not cost
less than $8-10 per liter. Anything less is indicative of lower quality. It must have a
sharp taste, as it’s rich in polyphenols. It must also smell fruity or like cut grass. When
examining the bottle, notice whether it was made in Italy, with olives cultivated in Italy. Also
check that it was made only by means of mechanical procedure, and not by any refining process.
Finally it’s important to know that olive oil lasts no more than 18 months,
or more conservatively 12, so check the harvest date. Oil must be sold in dark bottles and must
be kept away from heat and light. Unlike wine, it must be used right away, or it will begin to taste
slightly rancid. But who would want to wait when you’ve got this golden fluid ready to enjoy?
With your newfound appreciation of olive oil, it’s time to make some bruschetta and get to drizzling.