Food Science: Cloudy Olive Oil
Cloudiness in olive oil can result from naturally occurring sediment or from storage at cool temperatures. Some extra virgin olive oils are unfiltered and will appear cloudy at room temperature. This cloudiness is caused by sediment extracted from olives along with the oil during the pressing process. Arlene Wanderman of the International Olive Oil Council says this sediment which is nothing more than very small pieces of olives gives extra virgin oils added flavor and color. She notes that so-called light olive oils mild oils with little flavor or color are at the other end of the spectrum because they have been subjected to very fine filtration. Many unfiltered extra virgin oils are labeled as such and may have a stronger olive flavor than filtered oils. For this reason, do not filter cloudy extra virgin oils.
Cloudiness can also be caused by storage in the refrigerator or even in a cool basement. This type of cloudiness is the result of congealing saturated fat. Just like butter or chicken fat, the saturated fat in olive oil will harden in the refrigerator. However, since the amount of saturated fat in olive oil is so much lower than that in butter, the oil turns cloudy as opposed to hardening fully and turning opaque. To clear chilled oils, simply pour the desired amount into a measuring cup and let stand at room temperature for 15 or 20 minutes.