Some advice

In time, owing to its lipoid nature, extra virgin olive oil undergoes oxidation which can be accelerated by various factors such as high temperature or the presence of pro-oxidant metals.

In order to slow down this process it is important to preserve the oil following a few rules: keep the bottle away from direct light or heat sources; once the bottle has been opened, close it immediately after consumption in order to avoid contact with air; the oil must be consumed within a few months of opening; avoid transferring the oil from the original bottle to other containers, such as oil cruets, because the oil absorbs a lot of air and therefore, oxidizing, can lose taste and perfume; avoid topping up the oil cruet: old oil residue, after long exposure to the air and therefore oxidized, if not rancid, will quickly ruin the freshly added oil