Recognizing Rancid Extra Virgin Olive Oil in 2025: Signs and Prevention

Have you ever tasted a dish seasoned with extra virgin olive oil and noticed a strange, pungent, and unpleasant flavor? This is one of the first signs that you might be dealing with rancid olive oil. Determining whether your EVOO has gone bad isn't always easy, but with the right information, you can do so quickly and thus protect the quality of your recipes.

In this article, we'll guide you through the main signs that EVO oil is going rancid and give you some useful tips to effectively prevent it.

What Does It Mean When an EVO Oil Is Rancid?


Rancidity of extra virgin olive oil is a chemical process caused primarily by the oxidation of the unsaturated fatty acids present in the oil. This chemical reaction occurs when the oil is exposed for prolonged periods to external factors such as light, heat, and air, generating harmful compounds and altering its original flavor and aroma.

According to a study published in the Italian Journal of Fatty Substances, the presence of peroxides and aldehydes in extra virgin olive oil represents a fundamental indicator of its quality and health safety.

Peroxides form in the initial stages of the oxidation process: a high value indicates that the oil is starting to go rancid, compromising its organoleptic and beneficial properties. The maximum limit established for a quality extra virgin olive oil is equal to or less than 20 meq O₂/kg .

Aldehydes , on the other hand, are toxic compounds that develop when fatty acids degrade, especially if the oil is subjected to high temperatures for prolonged periods—as occurs, for example, during repeated frying. Some aldehydes , such as acrolein, are known for their irritant properties and potential harmful health effects.

An oil with high levels of peroxides and aldehydes not only loses its nutritional and sensorial value, but can also contribute to the development of oxidative stress and inflammation within the body.



Extra virgin olive oil being extracted | Frantoio D'Orazio

How to Know if Extra Virgin Olive Oil Has Gone Bad: Main Signs


Recognizing rancid olive oil is not difficult if you know the clear signs:

  • Pungent, unpleasant odor: often similar to paint, metal, or old crayons.

  • Bitter and pungent taste: a decidedly different taste from the fresh and fruity one of a good EVO oil.


To be absolutely sure, try a small taste test by pouring a small amount into a clean teaspoon and tasting it carefully.

What Are the Risks Associated with Rancid Oil?


Using rancid olive oil does not pose any serious immediate health risks, but it can cause:

  • Digestive disorders: due to the toxic compounds produced during oxidation.

  • Reduction in nutritional properties: antioxidants, vitamins and other beneficial substances decrease dramatically.

  • Deteriorating the taste of dishes: negatively impacting the final result of your preparations.


Preventing Rancidity of Extra Virgin Olive Oil: Helpful Tips


Prevention is the key to keeping extra virgin olive oil from going rancid. Here are some simple precautions:

  • Store the oil away from light and heat: use dark glass containers, opaque tins and use the EVO oil immediately.

  • Seal the containers well: to prevent air from entering, it would accelerate oxidation.

  • Buy EVO oil in small quantities: this allows you to consume it quickly and always maintain its freshness.


Frantoio D'Orazio and the Fight Against Rancidity


At Frantoio D'Orazio in Conversano, we take the quality of our extra virgin olive oil seriously. We apply rigorous procedures during production and packaging to minimize oxidation and rancidity. This ensures that each bottle retains its aromatic profile until it's opened at your home.

Don't risk ruining your dishes with rancid oil. Choose a product with guaranteed quality.

Buy Frantoio D'Orazio EVO oil now and enjoy its freshness!