How to know if an olive oil is in a bad shape?

Below we give you some clues to see if an olive oil is in a bad condition, apart from checking the preferential consumption date printed on the label:

1) The olive oil has a strange and unnatural color. Extra virgin olive oils have a range of colors that goes from an intense green to gold. Any color other than these may indicate that the olive oil is in a poor condition. 

For example, an olive oil packaged in a transparent glass bottle or PET that has been exposed to the sun or to an intense light in a shop for a long period of time can acquire a reddish tone similar to whiskey or cognac.

Another example, olive oils exposed to many frying cycles end up adopting a dark color, even with some foam.

2) Rancid smell and taste. Most of the olive oils in bad condition available to consumers will be rancid olive oils, that is, extra virgin olive oils that have been oxidized little by little, in the shops or in the kitchens, and consequently have ended rancid.

The rancidity process in an olive oil is something unavoidable, it will happens sooner or later, but it can be delayed with some good conservation practices

What is the rancid olive oil taste? 

The smell of a rancid olive oil reminds the smell of the varnish, the solvent, a freshly painted room, with a sweet smell. An olive oil is surely rancid if it has been open for more than three years and it stays during that time in a bottle.

Is it possible to remove the rancidity in an olive oil? 

It is not posible to recover an olive oil that is already rancid. It's rusty and it is irreversible. A mistake that can sometimes be committed is to try to mix it with another extra virgin olive oil that is in good condition to compensate the rancidity in the first one. That is not recommended because in the rancid olive oil there are already some components that may damage faster the fresh olive oil with which we have mixed it.

What is the preferential consumption date in an Extra Virgin Olive Oil? 

The preferential consumption date is fixed by the producer at the moment of packaging. He decides that according to the state of the olive oil and its analytical report, the conditions of conservation in the shop until its purchase by the final consumer.
For example, if the producer has a very stable extra virgin olive oil, like picual, packaged in an opaque glass bottle, you can trust that its properties and conditions of being extra virgin will be preserved for a longer period of time than those less stable extra virgin olive oils, like Arbequina, bottled in a transparent PET packaging. 

This way, the normal thing is to put dates of preferable consumption between 1 and 2 years.
It is important to emphasize that the preferential consumption date is not counted from the production of the olive oil but from its labelling and packaging date, so, It is posible to find extra virgin oils packaged on the same date but one could have been produced two years ago and other just produced, having both the same preferential consumption dates.