Olive oils should always be stored tightly capped, in a cool, dark place. A closed kitchen cabinet is fine. Prolonged exposure to light will reduce the shelf life of the product.
Refrigeration is not recommended for the following reasons:
The “Best if used by: (Date)” label is one of the ways we can make suggestions about how likely the quality of our product will remain consistent. This specific label is not meant to suggest that the item is unsafe after that suggested date. Instead, it refers specifically to the quality that can be assured under ideal and appropriate storage conditions for that item.
Here are some common questions consumers have about the appearance of their olive oil:
While any of these may be unpleasant to look at, the fact is, there is nothing wrong with the oil except that it was exposed to temperatures below 45 degrees in shipping or storage. This does not damage the oil in any way. It will return to its normal clarity and consistency, with no loss of quality, flavor or shelf life, when it is warmed to room temperature.
The authenticity of olive oil can be tested based on if and when it solidifies in a refrigerated environment.
According to North American Olive Oil Association, there is no simple magic home test to check for olive oil authenticity. Extra Virgin Olive Oil will crystallize and/or solidify at a wide variety of times and temperature exposures, based on the complexity of its makeup, which is affected by so many natural factors that vary by region, season and type of olive. Some of these include:
See also this great article from Olive Oil Times.
All this variance is what makes extra virgin olive oil truly special. So forget the fridge, and focus instead on enjoying the wide variety of flavors found amongst Extra Virgin Olive Oils.