A very common question among consumers of extra virgin olive oil is: Which oil is better, filtered or unfiltered?
The first thing we have to understandis, what is extra virgin olive oil. Extra virgin olive oil, hereinafter EVOO, is a natural product that comes directly from the olive. We could consider it olive juice, which, like natural orange juice, depends on the fruit being healthy for the result to be exquisite.
How is EVOO extracted?
Extra virgin olive oil is considered as such when the product comes directly from the olive and only by means of mechanical procedures.
Unfiltered EVOO is simply that olive juice without any treatment.
What are the processes to obtain Extra Virgin Olive Oil WITHOUT FILTERING?
There are two different processes for obtaining unfiltered extra virgin olive oil.
The first one is obtained just after the cleaning of the vertical centrifuge, a mechanical and instantaneous way of separating the water from the extra virgin olive oil. The second one is by decanting chain, it is left through several communicating glasses that by density and decanting, worth the redundancy, the impurities are eliminated in the first glasses and when leaving the last glass we will obtain the extra virgin olive oil without filtering for its bottling.
This gives the EVOO an intense green, cloudy and dense aspect that we EVOO lovers like so much. This magnificent characteristic is due to its chlorophyll content, natural humidity and micro-impurities from the fruit itself. As time goes by, with the rise of environmental temperatures, this turbidity will end up deposited at the bottom of the container, leaving the EVOO clean and with a putty at the bottom of the container, which is called “posos” (dregs).
Process for FILTERED Extra Virgin Olive Oil.
The filtering process is carried out through cellulose (paper) plates through which the unfiltered extra virgin olive oil passes and these plates trap moisture and micro-impurities leaving the oil shiny and clean allowing the EVOO to maintain its quality (provided it is well preserved in a cool, dry place) for much longer.
Remember that in the filtering process neither flavors nor aromas are lost. Density and some green color are lost. A good filtration should not vary neither the quality nor the composition of the original unfiltered EVOO.
Sometimes, even when filtered, it may present some turbidity and should be removed after a short period of time or when the ambient temperature rises a little.
Is it better to buy unfiltered extra virgin olive oil or filtered extra virgin olive oil?
It depends a lot on the consumption habit and it must be taken into account that the quality does not influence this concept as long as we are talking about extra virgin olive oil.
If you like fresh unfiltered oil, take advantage of acquiring it at the beginning of the season when the mills begin to market it. Choose medium and small mills where the processes are very careful and the cleanliness is maximum. This is how you will be able to taste fresh and unfiltered extra virgin olive oils, the richest that olives can offer you. This is how we do it in our Pago las Monjas olive mill to elaborate ourextra virgin olive oil “Previo”. An incredibly healthy, natural oil, obtained from a selection of our early oils harvested to obtain a surprising aroma and flavor.
Buying with the consumption period in mind
They are not EVOOs to buy for the whole year because, as mentioned above, when ambient temperatures rise, the unfiltered EVOO will decant and accelerate the oxidation process that occurs when vegetable matter, temperature and humidity come together at the bottom of the container.
The recommendation is to calculate the consumption of this unfiltered EVOO over a period of no more than 6 months from the time of purchase and store it in a cool, dry place without sudden changes in temperature.
For the rest of the year, it is recommended to buy filtered EVOO. Filtered and well preserved EVOO can maintain its quality for up to 18 months (Picual variety) after bottling.
Taste differences between filtered and unfiltered extra virgin olive oil.
Being the same olive juice the one that is filtered and the one that is not, there does not have to be so much difference. It is true that some of the flavor, provided by those micro-impurities and moisture, is lost in the filtering process. The sensation of density in the mouth that unfiltered extra virgin olive oil offers us can only be offered by it.
The important thing is that it is an EVOO from the months of October, November or at the latest mid-December in order to enjoy a delicious product with all its organoleptic and healthy values. Whether it is filtered or unfiltered extra virgin olive oil, its flavor and composition will depend mainly on the olives being healthy, carefully harvested, transported and transformed quickly so as not to lose any of the fruit’s original values.
Health properties of filtered and unfiltered EVOO
It is clear that unfiltered extra virgin olive oil is a product to be consumed quickly, its content in polyphenols, oleocathal, Tirosol and other chemical parameters, make that the health value of extra virgin olive oil does not depend on the filtering. Some residual part of these parameters may be eliminated in the filtering process, but it is not representative to consider that filtering makes an oil healthier than an unfiltered one.