What is unfiltered extra virgin olive oil?
Unfiltered extra virgin olive oil is natural olive juice that is bottled without going through the filtering process. This makes the oil appear cloudy because it contains water and suspended particles. It is also referred to as fresh olive oil or olive oil in its raw state.
How does the filtering process work?
Once the olives arrive at the mills, they are classified according to variety, condition of the olives, degree of ripeness, etc.
Next, they go to the milling process, which is the process by which the olive is split and crushed to release the juice. This can be done using traditional stone mills, which are now obsolete, or, as most mills do today, with metallic mills or crushers that can be hammers, toothed discs, or ribbed roller mills.
The resulting paste from milling goes to the kneading phase to obtain the oil. The oil droplets form a more extensive, more easily separable oily phase from the aqueous phase (olive water) and the solid phase or pomace (skin + pulp + broken stones).
In the filtering process, the oily phase is separated from the water (aqueous phase) and solid parts (solid phase). The most commonly used system today is “centrifugation”. The olive paste is placed in a horizontal cylinder and spun quickly. In the absence of air and along the length of the cylinder, the pomace, water, and oil are separated by density differences.
Advantages of unfiltered extra virgin olive oil
- Freshness: Unfiltered extra virgin olive oil guarantees that the oil comes from the latest olive harvest. Within 4 to 10 months after harvesting, the oils naturally settle in the tanks, and after those months, their appearance is the same as filtered oil.
- Retains additional polyphenols: Polyphenols are natural antioxidants, and unfiltered oils retain extra polyphenols found in water quantities that have not been removed.
Disadvantages of unfiltered extra virgin olive oil
- Less attractive appearance: These oils are cloudy compared to the bright and translucent filtered oils.
- Preservation: Since unfiltered oils naturally settle and sediment at the bottom, these sediments can impart some smell to the oil, which does not mean the oil has gone wrong. Therefore, it is recommended that you consume it within the year.
How to consume unfiltered or raw olive oil
To enjoy its fresh and fruity flavour, you should use it on toast, salads, etc. It is not recommended for frying since the high temperatures can quickly burn the organic substances that haven’t been filtered out.
When to buy unfiltered oil
Unfiltered oils are mainly available between October and December when the olive harvest occurs. It is recommended that you buy them at this time.
It is not advisable to buy it after May, as the heat oxidises it, causing it to lose its properties more quickly.
Quality of unfiltered or filtered olive oil
As mentioned in the tasting post, colour is not an indicator of quality. It depends more on personal preference.
The quality of extra virgin olive oil, whether filtered or unfiltered, depends on the fruit´s quality, the production process´s rigour, and its preservation. These factors ensure a high-quality extra virgin olive oil.