Can you freeze olive oil? What is the freezing point?
There are myths about freezing olive oil sources.
We get a lot of questions about freezing olive oil, such as, what are the clouds in my olives, is it good or bad for it, and does the way it is frozen say anything about it.We tried to clarify the issues.
The temperature in the refrigerator is usually set to around 37F.The freezing point of pure oleic acid is listed in chemistry texts.Olive oil manufacturers don't usually list a freezing temperature because it is quite variable depending on the olive variety.Olive oil is made up of hundreds of chemicals, many of which change over time.
Like most fruit, olives have waxes on their skin to protect them from insects.Natural waxes allow apples to be shined.If an oil is sent to a cold climate, or if it will be used in a product like salad dressing, it is often "winterized" to remove the waxes and steparates.If olive oil is sufficiently winterized, it is a good idea to put it in an ice water bath for 5 hours.There should be no clouding or crystals.
Oil that has not been winterized will clump and form needle-like crystals at refrigerator temperatures as the longer chain fats and waxes in the oil congeal, but it will not harden completely unless chilled.Some olive varieties form waxes that produce long thin crystals, others form wax that congeal into rosettes, slimy clumps, clouds, and a swirl of egg white that the consumer may fear represents spoilage.During the winter when oil is exposed to cold temperatures, these visual flaws may form outside the refrigerator.The hardened oil has a white color.
When olive oil is warmed, it will return to its normal consistency.The ideal temperature to store olive oil is 50F.
To determine the freezing temperature, Dr. John Deane put oils in the freezer.Most of the oils had not hardened.Most were as soft as butter at room temperature, even though they could not be poured.The oil solidified as the temperature dropped.The oils were hard enough that a fork couldn't penetrate them.Determining what point to call the oil "frozen" is not easy.This slow increase in hardening as the temperature is lowered is in sharp contrast to a pure substance such as water that can be switched from liquid to solid phase at an exact temperature.
Hardening is a myth.There is a rumor that a small amount of extra virgin olive oil, placed in a glass bowl and refrigerated for a while, would become crystallising.When frozen, a block of olive oil with some virgin oil added would form.
At the Olive Oil Source, we don't think this is a valid observation.While refined or pomace oils will usually be stripped of their waxes, thus making them more likely to form a block, and while it is more common for a refined oil to be winterized to being used in a cheap dressing, many excellent extra virgin oils do not form "crystals".We have watched the production process of many premium oils, from the olive to the bottle, which form a solid block when frozen.It is more difficult to detect fraud than freezing the oil.
There is a myth that Olive Oil Hardens in the Refrigerator means it is Saturated.There is no saturated fat in olive oil.If they get cold enough, saturated fats will become hardened.Olive oil is often hardened, but not because it is saturated.As seed oils have been, it has not been refined to remove waxes.The presence of waxes doesn't mean olive oil is bad, it just means it is a natural product.
The more saturated the fat, the harder it will be at room temperature.The saturated tropical fats in cookies, packaged foods, and snack foods are all solid at room temperature.This improves shelf life, makes packaging easier, and improves "mouth feel" but is not good for your health.