Understanding Extra Virgin Olive Oil (EVOO)

High Phenolic Certified Extra Virgin Olive Oil

Not all extra virgin olive oils are equal when it comes to polyphenols or antioxidants.  Some olive cultivars have higher polyphenols than others.  And, depending on how green or how ripe the olives are at harvest, and how fresh the olive oil is can have an  impact on polyphenol levels.  A high polyphenol level in olive oil is important because the higher the level the more micronutrients (antioxidants) are present in the oil.  Unfortunately, polyphenol levels are not a required measurement for extra virgin grade. And, polyphenol levels are not required to be listed on the label.  All olive oil is a monounsaturated fat.  So, it is a good fat and it contains lots of oleic acid which are both beneficial for cardiac health.  However, only high polyphenol (High Phenolic) extra virgin olive oils offer the additional health benefits of anti-inflammation and anti-oxidation properties that benefit human cells.  

Eric and Candace Kaltenbach

Certified Extra Virgin Olive Oil

To be certified extra virgin, the olive oil is tested in a laboratory to ensure that the olive oil meets or exceeds the standards for Extra Virgin Grade.  California has the most stringent standards as compared to the USDA or international standards.  If the olive oil passes the laboratory or scientific standards, then the olive oil is taste tested by an expert sensory panel to ensure there are no flavor defects, which could be missed by the scientific instruments.  Flavor defects stem from poor olive quality at the time of milling, poor handling of the oil post milling, from dirty or poor bulk storage containers or from storage facilities that are not temperature controlled.  The California Olive Oil Council (COOC) is one of the most reputable and stringent certifying organizations in the United States and olive oils that carry the COOC Seal have fully met or exceeded the COOC standards. 

Extra Virgin Olive Oil is the Juice of the Olive

Pure and simple, extra virgin olive oil is the fruit juice of olives.  It is pressed directly from olives using only mechanical means.  No chemicals can be used to aid in the extraction of the oil.  The extraction process must remain below 82 degrees (Cold Pressed) and it must be the first pressing.  Lower grades of olive oil can be obtained from second presses using higher temperatures.       

Filtered vs Unfiltered

When olives are milled and after the oil is extracted, there is still some olive sediment and moisture present in the oil.  The olive sediment is heavier than the oil and eventually settles on the bottom of the bulk storage drum.  This olive sediment oxidizes quickly and it will make the olive oil taste musty.  So, the olive oil must be racked (removing the clean oil from above the sediment) into a clean storage container or bottle.  Although this is the traditional method for removing the sediment, it does not remove all of the residual moisture and micro-organisms that can attack the remaining polyphenols, create a musty flavor, and lower the oils effective life span.  

Filtering the olive oil just after milling removes the olive sediment, moisture, and mico-organisms from the oil.  If filtered properly, the flavor of the oil and the over 90% of the good polyphenols remain.  Studies have shown that filtering helps preserve the remaining polyphenols in the olive oil.  And, since we now know that it’s the polyphenols in olive oil that provide the best health benefits, we need our olive oils to retain the maximum amount of polyphenols possible.  Also, filtered olive oil has a cleaner, fruitier flavor over a longer period.  

Thus, in the case of premium olive oils (oils used for salad dressings or poured over foods), filtered olive oil is healthier and tastes better. 

Purchasing Olio Nuovo (unfiltered) at harvest time is a real treat to experience the fresh grassy bitterness of fresh olive oil.  This is an Italian tradition of celebrating the olive harvest.  Just remember that Olio Nuovo needs to be consumed quickly before the olive sediment in the bottle oxidizes and taints the flavor of the olive oil.    

Other Grades of Olive Oil

Olive Oil grade or refined olive oil is obtained by pressing the olive paste, typically using high temperatures, following the first cold press.  This olive oil is still provides a mono-unsaturated fat benefit, but looses most of the other health benefits.

Flavored olive oil, such as rosemary or lemon, are created using one of two methods.  Either co-milled, pressing the herbs or fruit along with the pressing the olives, or infused, which typically involves heating the oil with the herbs or fruit added to infuse the flavor into the oil.  The co-milling method is the better method for flavoring olive oil because it extracts the oils from the herbs or fruit and mixes with the oils obtained from the olives.  When cooking with flavored olive oil the co-milled flavors will generally remain after cooking, where-as the infused flavors are generally lost after cooking.  Consumers need to be cautious when purchasing flavored oils.  Some olive oil producers use the herb or fruit flavoring to mask flavor defects or other defects in an oil that would not otherwise be able to achieve the extra virgin grade.  Also, some of the olive cultivars that are used for the flavored oils typically have lower polyphenol levels, which don’t provide the best health benefit and shorten the oils shelf life.  Our recommendation is to purchase the highest quality certified extra virgin olive oil possible and then add your own herbs or fruit juices to that oil at the time of serving.  This assures that you are obtaining the best health benefits possible from your olive oil.