Filtered Olive Oil
Talking to many consumers, the question of what the difference between filtered and unfiltered olive oil is always arises. It is a good question, and to answer this query, we have asked a wide variety of people from the scientific community all the way to the people who work in the industry for their perspectives
All of them were in agreement that the process of olive oil production ends with a product (oil) in which, in suspension, are tiny particles of olive oil (pulp and stone) that give the classic look of murky raw oil, freshly pressed. If you let unfiltered olive oil “sit” for a couple of months in a container, this sediment will fall to the bottom through the natural process of gravity and look like a black layer. To clarify this point, this sign DOES NOT mean that the olive oil is dirty or ruined. It is just a testimony to its authenticity and genuineness of the product. Moreover, the people interviewed said the presence of these micro-particles in oil tends to make an improvement with respect to the healthy nutritional content typical of extra virgin olive oil, albeit there was a disagreement on how much of an improvement there is.
Thus, the question remains, why do producers filter the oil? Well, the main reason is that these particles reduce the shelf-life, or conservation, of the olive oil. The processes of fermentation of these particles will in fact cause the creation of what is technically known as “sludge”, whereby olive pulp is fermented, rotting.
Therefore, to summarise, unfiltered oil, if on the one hand, is more genuine and healthy compared to a filtered one, on the other it must necessarily be consumed in a short time to avoid creating the defects just discussed. This is the give and take of the two processes.
In the end of it all, this is what you should know about this topic. If you happen to find new oil, which means finding it during oil extraction season (September through January), and if you plan to consume it in a relatively short time (within a few months), then go ahead and buy raw, unfiltered olive oil. Otherwise, if you shop at a supermarket, choose to buy a filtered one because it is your best bet to obtain a quality olive oil with a minimum reduction of its health benefits.