You’re about to pour it in to your salad dressing shaker or smoothie, but you suddenly remember you’ve had this bottle a while and you wonder, is my olive oil SHOT?  We’ve got your answers here!

How Does Olive Oil Go Bad?

First, we have to understand what actually causes extra virgin olive oil to go bad – and there are several factors.  The big four are easily remembered by the acronym : “SHOT”:

  • S – Sunlight :  If your bottle is clear, this could be a problem.  Always buy dark green or smoke colored bottles that keep the sunlight off of your oil.
  • H – Heat :  Has your oil been too close to the stove?  Keep your oil at a distance from the stove – a couple of feet away from the burners is perfect. 
  • O – Oxygen / Air : Is the cap loose?  Keep your bottle cap tightly sealed when not in use.  Be careful with special or decorative bottles that are clear and do not seal well.
  • T – Time : How long have you had it?  Most good EVOOs have a 12-24 month shelf life or Best By life.  Good storage conditions will keep your oil from going rancid but time will eventually deplete the good polyphenols in your olive oil.

For more info on exactly how it breaks down read our blog here:  Can Olive Oil Expire?

Bad – or Just Old?

So how do you know if your oil is actually “bad” or rancid – or it’s just tired and old and you are notgetting the health benefits you initially paid for?

Bad, or rancid olive oil is pretty easy to detect.  When I was younger I asked a wine sommelier if I would be able to detect “bad” wine? He said, “You’ll know it when you taste it!”  So, when you taste your olive oil, does it taste or smell like crayons, putty, or Elmer’s glue — instead of the bright, fruity olive-y taste you originally bought?  Also, tasting your olive oil like this, especially your EVOO – extra virgin olive oil, immediately when you buy it is a great idea.  That way you know what it is supposed to taste like each time you use it.

Second, if it is rancid, rest easy if you used it yesterday before you read this article!  it is well accepted that rancid olive oil will not hurt you.  It might ruin your next great food dish – but the oil itself will not hurt you.  The smell of being rancid seems to be caused by the emergence of three primary compounds: Nonanal, Hexanal, and Pentanal.  None of these forming in your bottle of olive oil is enough to hurt you or be toxic.

And if it still tastes ok but is way past its “Best By” date or “Expiration Date” (which by the way, it should have or you need a better brand of olive oil!), then does it matter?  It matters because the European Food Safety Authority (EFSA) has determined that a minimum 5 mg of hydroxytyrosol and its derivatives in olive oil should be consumed daily by individuals – or to be used by olive oil producers to use a cardiovascular health claim.  5mg levels of hydroxytyrosol can be hard to achieve with standard olive oils or tired, old olive oils.  The natural hydroxytyrosol, tyrosol and other healthy active ingredients are actually a little unstable and will break down over time even under the best conditions.

So Now What?

So now you know how to evaluate your olive like a pro, and next time you will know how to buy it like a pro.  Just be sure to use regularly to keep it fresh and get the health benefits!  And try our polyphenol-enriched extra virgin olive oil here next time!

* Disclaimer: These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.