Did you know that olives are actually fruit, and that extra virgin olive oil is one of the few natural juices used and preserved without any chemical additives? Here we are talking about true extra virgin olive oil, as there are many declared extra virgin olive oils on the market that are not genuine.
To obtain such high-quality oil from olives, a series of important procedures and elements need to be carefully managed during cultivation, processing, and storage.
Before harvesting, olive growers put in a lot of effort to cultivate healthy olive fruit, ensuring that each tree bears a good crop, meaning consistent fertility every year, as olive trees are sensitive and prone to large annual fluctuations in fruit yield.
One of the key steps is quality and timely pruning of the olive tree. It’s said that the better you prune the olive tree, the more fruit it will yield. And this is not simple – it requires significant knowledge to remove excess branches while preserving the key ones, directing the olive tree’s growth and development correctly.
Once we have healthy olive fruit, we’ve tackled just the first of many important elements. Next is the crucial timing of olive harvesting. It’s well-known that, unlike in the times of our grandparents, olives are harvested when enough oil has formed in the olive fruit, but the fruit hasn’t entered its final ripening stage yet. Additionally, each olive variety has its own ripening time, which must be taken into account.
Olive harvesting is one of the most emotional stages of oil production. There’s much debate over whether olives should be picked by hand or with machinery, but the main question is – how can we minimize damage to the fruit during harvesting?
Traditional manual olive harvesting is slow and inefficient even by modern standards. That’s why manual shakers, rakes, and various handheld tools are used. However, there’s an increasing number of machines on the market that can accelerate olive harvesting by up to ten times, while minimizing damage to the olives.
If olives are taken for processing immediately after harvesting, the risk of spoilage is minimal. This brings us to the third important element in obtaining high-quality extra virgin olive oil. After harvesting, olives need to be taken for processing as soon as possible, within 48 hours at the latest.
In the past, olives were stored in cellars after harvesting, waiting for their turn to be processed and to further soften. Today, we know this is not good at all, as it leads to spoilage of olives and subsequently the oil obtained from them. In some regions, olives were also put in the sea for the same reason, but this practice is no longer in use. Smaller quantities of olives were processed at home by mashing softened olives.
One of the most delicate steps in creating top-quality oil is the olive processing method. Modern technology and advanced olive processing machinery have enabled us to obtain excellent quality olive oil. Watch this short video.
In these machines, the temperature of the production process never exceeds 27 degrees Celsius, as higher temperatures can destroy essential polyphenols in the olive oil. The modern processing method differs from the traditional one in various aspects.
We often hear the question – is this olive oil cold pressed? Today, this question is irrelevant, of course, if the oil is produced using modern machinery, as the processing temperature doesn’t exceed 27 degrees Celsius, which is why this process is called the cold method.
The traditional processing method involved pressing olives while pouring hot water over them to facilitate easier extraction of the oil from the olive fruit, which was detrimental to the oil’s quality.
According to the traditional method, olives were first put into a mill, where they, along with the pits, were ground into small pieces, creating olive paste or olive dough. The resulting mixture was then placed into woven baskets, which were stacked vertically in a pressing machine.
With pressure, the oil mixed with hot water was squeezed out, followed by the separation of oil from water. The process was extremely difficult and time-consuming, resulting in low-quality oil.
In modern machines or olive processing devices, the production process is much faster and easier. The entire process is enclosed, and the stages within the machine follow one another without interruption.
The milling process takes about ten minutes, depending on the type of machine and its capacity, while the pressing of olives and oil extraction have been replaced by several different steps.
After grinding, the olive paste is mixed for about twenty to thirty minutes, during which oil molecules come together to form oil. This mixing process is also crucial as it determines the aromatic profile of the olive oil.
Afterward, the separation of the obtained oil from the remaining mixture, known as olive pomace, takes place in a centrifugal separator.
The final phase in olive processing involves separating the oil from the vegetable water. Since these are two liquids that don’t mix, separation is quick and simple with the help of vertical centrifuges.
Filtering is the last step in which most olive growers use cellulose filters immediately after processing, while some opt for traditional filtering later by pouring the oil.
If olive oil hasn’t been filtered immediately after processing, it will be cloudy due to containing small water particles and pieces of fruit left over from processing.
There are common questions about whether oil should be filtered and what happens if it isn’t. There are valid arguments for both sides. If the oil is filtered immediately, it will be more stable, and the likelihood of oil spoilage over time, which leads to a decrease in important elements like polyphenols, will be lower.
However, by filtering the oil and removing residual particles, we also remove part of these quality components.
In short, for smaller quantities of olive oil that will be consumed quickly, filtering is not necessary. Instead, after some time, when the oil settles and the particles sink to the bottom, the oil can be transferred, and the particles removed.
For producers of larger quantities of oil destined for sale, immediate filtering is definitely the better option.
Olive oil should be stored at around 15 degrees Celsius, in a dark place. Stainless steel barrels are used, and oxygen is removed from them by adding nitrogen, ensuring the oil remains completely sealed until bottling.