Two European researchers have conducted experiments under different environmental conditions (light, temperature, different containers) on the shelf life of extra virgin olive oils (EVOO).
The results, published in the European Food Research and Technology magazine (Shelf-life predictions registration for olive oil packaged using flavour compounds as markers) are very interesting and may be summarised in two sentences.
If your extra virgin olive oil is contained in a sealed glass bottle and stored at less than 20°C away from light (and given a 50 % decrease in the quality indicator, i.e. half the point where oil is deemed to reach inadequate oxidation), the shelf life is greater than 24 months. This is especially the case if the oil initially has a very low acidity, and if it contains a high level of antioxidants (present naturally in olive oil).
However, in the case of a black olive oil (green olives contain more antioxidants) harvested late in the season (more antioxidants are found before the complete maturity of olives) and where the oil has not been filtered and where the container has been opened, it will be good for only a few months!
