There are two types of analysis that is performed to determine the quality of olive oil. First it’s the chemical tests and then the taste tests. On this post I will explain how you may understand if an olive oil is extra virgin or not.
Not all labels will contain this information even though this is the most important value that determines if the olive oil is extra virgin, virgin or plain olive oil.
Accorging to Claudio Peri (Professor Emeritus in Food Science and Technology at the University of Milan, Italy) the presence of free fatty acids in olive oil is caused by a reaction (lipolysis) started when lipolytic enzymes (that are normally present in the pulp and seed cells of the olive) come in contact with the oil (that is contained in particular vacuoles) due to loss of integrity of the olive. High values of free acidity in olive oil can be due to different factors such as: production from unhealthy olives (due to microorganisms and moulds contamination or attacked by flies and parasites), bruised olives, delayed harvesting and storage before processing. The lipolysis reaction is greatly enhanced by the presence of an aqueous phase, so when oil is separated from water during processing, lipolysis slows down and stops.
In other words, the lower the acidity the better!!
When the acidity is less than 0,8%, then the olive oil is Extra Virgin Olive Oil (just like Silikia!)
When the acidity is between 0,8-2%, the it is categorised as Virgin Olive Oil.
Anything above 2% is just Olive Oil. This type of olive oil is usually mixed with herbs, garlic or peppers.
If you don’t see the acidity written on the label, then it’s probably not extra virgin. There is one thing you need to know about olive oil producers of extra virgin olive oil. We are always proud of our oil and would always include the acidity of our olive oil on the label!
There are many factors that determine the acidity.
- First of all, the olive trees must be happy! The climate of the region plays crusial role. There must be plenty of sunshine, no ice during the winters and no rain during summer. With proper care, olive trees can live hundreds of year.
- Then there are illnesses and insects that can affect the trees and the quality of the production. Αgriculturists are always needed to individually assess each olive grove every year. Then, depending on the type of the grove (if it’s meant to produce organic or not) they decide on what protection the grove will receive. The most common insect that affects the olives is Dacus or olive fruit fly.
- During the harvest, the olives must be collected gently to avoid bruising and when all of the olive fruits are placed in linen sacks, the trees must be prunned by someone experienced in order to help the tree stay healthy.
- The olives must be sent to the olive mill and into processing within one day from harvesting. The more the olives stay in the sack, the more acidity of the olive oil they will produce.
- During processing, the pulp should be cool, always in room temperature, and for the final step, the separation between water and oil must be absolute.
In our olive mill, we pride to follow a very strict regime to keep our olive trees healthy and our production always of the finest quality. This is why our olive oil has always been Extra Virgin,
and you can see it on the label!😉