How to Tell If Your Olive Oil is High Quality

How to Tell If Your Olive Oil is High Quality

Discovering a high-quality Extra Virgin Olive Oil (EVOO) can both elevate your culinary experience and boost your health. From flavor nuances to health benefits, understanding what makes a good EVOO is essential for anyone. Here are some of the key points to consider when looking for a high-quality, authentic EVOO. These factors are what makes Kosterina EVOO standout from the rest.

High Polyphenols

Polyphenol content in extra virgin olive oil is what makes EVOO so healthy. Polyphenols are powerful antioxidants with proven health benefits. They protect cells from damage, reduce inflammation, and have been shown to lower the risk of chronic illnesses like heart disease and cancer. Including polyphenols in your diet through extra virgin olive oil supports overall well-being and longevity.

Kosterina Extra Virgin Olive Oil has a polyphenol content of over 625mg/kg. To put this into perspective, a polyphenol content of 220mg/kg or greater is generally considered "high." In order to be considered "extra virgin," an oil requires 55mg/kg of polyphenol content.

Robust Flavor

Just because something is healthy, that doesn't mean you have to sacrifice on delicious flavor. In fact, bold flavor can be an indicator of how nutritious an EVOO is!

Robust flavors come from the higher concentration of polyphenols, antioxidants, and other beneficial compounds. Unfortunately, here in the United States, our industry is overrun with fraud and "fake" EVOO. In fact, when our founder first tried olive oil in the US, the first thing she noticed was the lack of the beautiful flavors she was used to in Greece. This is what the standard American consumer may be used to, but we can tell you that EVOO should taste flavorful and natural. 

Kosterina Extra Virgin Olive Oil is always early harvest and harnesses the peppery, herbaceous notes of the Greek Koroneiki olive (which is naturally higher in polyphenol content). This results in a full-bodied, flavorful EVOO that can not only stand on its own, but elevate the taste of whatever food you make with it. 

Safe Packaging

As a general rule of thumb, you should not buy EVOO packaged in plastic. Plastic containers can compromise the quality of EVOO over time by allowing chemicals to leach into the oil, affecting its flavor and beneficial properties. Olive oil is corrosive to plastic and it is not uncommon for microplastics to take over your delicious liquid gold.

Additionally, exposure to light and air through plastic packaging can accelerate oxidation, leading to rancidity and diminished health benefits. This is why we always package our EVOO in opaque glass or aluminum (just like they do in Europe).

To ensure you get the best-quality EVOO, choose bottles that are made of dark glass or tin to protect the oil from light and maintain its freshness and nutritional value.


The harvest date is crucial when choosing Extra Virgin Olive Oil (EVOO) as it indicates freshness and quality. Many oil bottles in grocery stores have older (if not undisclosed) harvest dates.

Knowing when the olives were harvested helps us gauge an oils freshness. Fresher, newer harvest EVOO typically retains higher levels of antioxidants and polyphenols, which degrade over time. By selecting oils with recent harvest dates, you ensure you're getting the most flavorful and nutritious EVOO available. We provide the harvest dates on all of our bottles, only providing the latest harvest to maximize flavor and health benefits. 

Pro-tip: Look for harvest dates in November/December of the previous year, which mean you are getting early harvest EVOO!

Single Origin

Single origin Extra Virgin Olive Oil denotes that the olives used to produce the oil come from a specific region or even a single farm, ensuring consistency in flavor and quality. Single origin EVOO allows for traceability and transparency in production practices, highlighting unique terroir influences that contribute to its distinct taste profile.

In our industry, we often see vegetable, seed, and even olive oils blending olives from several different regions. While this may save on costs for the producer, this also creates an inconsistent flavor, and often indicates a use of lower-quality ingredients. 

We commit to the use of single-origin 100% Koroneiki olives from southern Greece. Our groves are family-owned and operated, maximizing on authentic flavor & sustainable farming practices.