How to keep Olive Oil from becoming bad?


Incorrect storage of olive oil can influence the sensory and nutritional quality of the oil.  The olive oil will become rancid and off-flavors when it went bad. One of the biggest factors of olive oil quality deterioration is lipid oxidation. And, the rate of the lipid oxidation depends on the availability of oxygen, the presence of light and the temperature, which are the three biggest enemies of olive oil deterioration.



Researcher Jamie Ayton at the Australian Oils Research Laboratory


Source: OliveOilTimes

''A 3 years study by Australian scientists confirms that oxygen, light and heat are indeed among extra virgin olive oil’s worst enemies.''

by Olive Oil Times

Oxidation is a cellular process that can speed up the breakdown of fat molecules in olive oil. When this happens, the olive oil will slowly lose some of its potent antioxidant properties. The oxygen-containing molecules will trigger a chain of chemical reactions that can break down the antioxidants in the oil. 



Extra virgin olive oil can be very expensive in the market, hence, a lot of people are tempted to buy it in a large bottle. However, the bigger the bottle is, the more time the olive oil in contact with oxygen and the higher the risk of your olive oil to become rancid before you use it. 


Oxidation with absence of light is called Auto-Oxidation. While, the oxidation in the presence of light and oxygen is called photo-oxidation. Thus, direct light can have damaging effect on your olive oil which is why so many of the olive oil is packaged in dark glass or an opaque material bottles to prevent photo-oxidation happens and losing its nutritional qualities, especially alpha tocopherols (Vitamin E).


When you store your olive oil over time at higher temperature place. The compounds in olive oil that cause pleasant flavors and aromas will lose. The rancidity will develop sooner and free fatty acid levels will rise faster.






  1. Choose the size of olive oil according to your consumption rate when in grocery store. Recommended to choose the olive oil which can be used up in a month or not more than a year from the bottling date.
  2. Transfer the olive oil to smaller dark color glass bottle or dispenser with low headspace if buy in bulk. Before filling into smaller bottle, ensure that the bottle is dry and does not have any traces of old oils that might give it a rancid flavor and spoil the taste of the fresh olive oil.
  3. Make sure you tighten the cap of the bottle after you used it. To avoid more oxygen to contact with the olive oil. 

  4. Keep your olive oil in a dark place. Do not directly expose to sunlight. 

  5. Recommended to buy olive oil in dark color glass bottle or tin containers (if in bulk).   

  6.  Keep your olive oil in room temperature. Recommended to keep it less than 25 degrees C.

  7. Avoid to put your olive oil beside the windows and stove. Should store in cabinet or in refrigerator. Keep in mind that the olive oil will become solidified and look a bit cloudy if you store in refrigerator. It is normal reaction and doesn’t indicate the olive oil has spoiled.

  8.  Try to avoid sudden changes of storage temperature.