The Essential Guide to Extra Virgin Olive Oil

What makes an olive oil ‘extra virgin?’ How is EVOO made, and why is it the healthiest cooking oil? We have answers.

By Daniel Dawson
Jan. 20, 2022 11:09 UTC
22K reads

Extra vir­gin olive oil can be con­fus­ing, but it does­n’t need to be. Understanding what makes this elite grade of olive oil so spe­cial comes down to a few basic facts.

Extra vir­gin olive oil is the high­est qual­ity of olive oil and is gov­erned by the most strict chem­i­cal and organolep­tic stan­dards.

As a result, EVOO pro­vides the most health ben­e­fits and is the most fla­vor­ful of the nine grades of olive oil.

See Also:Olive Oil Basics

Extra vir­gin olive oil is also the tough­est to make and requires both chem­i­cal and organolep­tic assess­ment, mak­ing it the most expen­sive grade of olive oil to pro­duce.

However, any­one who has tasted high-qual­ity extra vir­gin olive oil knows it is worth all the trou­ble.

What extra vir­gin’ really means

The Codex Alimentarius and International Olive Council (IOC) – the two main sources of gov­er­nance over olive oil qual­ity – define EVOO as hav­ing excel­lent fla­vor and odor.

To be extra vir­gin,’ an olive oil must have a median of defects – or the median score of one of the 12 olive oil defects, which is per­ceived with the great­est inten­sity – as zero, and the median of fruiti­ness above zero (but more on that later).

Extra vir­gin olive oil also has a free fatty acid con­tent expressed as oleic acid less than 0.8 grams per 100 grams, the low­est of any non-refined grade of olive oil. (The refin­ing process removes free fatty acid, which is why refined olive oils have less.)

Generally, the higher val­ues of free fatty acids indi­cate that the triglyc­erides, which bind three fatty acids to a glyc­erol back­bone, have bro­ken down. This hap­pens when olive oil is made with dam­aged or dis­eased fruit, there are delays in the milling process, the oil is exposed to high tem­per­a­tures or other poor stor­age con­di­tions.

While 0.8 grams per 100 grams is the high­est accept­able amount of free fatty acids in extra vir­gin olive oil, many of the high­est-qual­ity EVOOs have a free fatty acid con­tent closer to 0.3.

Along with the free fatty acid con­tent, the mil­liequiv­a­lent per­ox­ide oxy­gen per kilo­gram of the oil must also be less than or equal to 20. The higher the per­ox­ide value recorded, the more oxi­da­tion that has already taken place and the less time the oil is likely to be fresh.

While most gov­ern­ments fol­low Codex Alimentarius and IOC stan­dards, the def­i­n­i­tion for extra vir­gin olive oil is more strict in California, which per­mits a free fatty acid con­tent expressed as oleic acid less than 0.5 grams per 100 grams. However, the organolep­tic require­ments remain the same.

You can taste the dif­fer­ence

Away from the chem­i­cal para­me­ters, extra vir­gin olive oil is also judged by the mag­ni­tude of its three pos­i­tive attrib­utes and the absence of five com­mon defects.

EVOO’s pos­i­tive attrib­utes – fruiti­ness, bit­ter­ness and pun­gency – are deter­mined by a trained tast­ing panel using a lin­ear scale to rate its inten­sity.


Fruitiness is deter­mined by an oil’s aroma and taste. It is often described as fresh, green, mature and ripe.

On the other hand, bit­ter­ness is per­ceived on the tongue and is a less sought-after fla­vor in most foods.

However, its pres­ence indi­cates that an extra vir­gin olive oil has been made with fresh olives and is full of polyphe­nols. As with cer­tain types of beer, choco­late and cof­fee, bit­ter­ness is an acquired taste. A true appre­ci­a­tion of the fla­vor comes over time.

See Also:Certain Food Proteins Reduce Bitterness and Pungency of EVOO

The third pos­i­tive EVOO attribute is pun­gency, a sting­ing sen­sa­tion in the back of the throat and asso­ci­ated with the pres­ence of oleo­can­thal, a polyphe­nol. Pungency, which has a sim­i­lar sen­sa­tion to that of chili pep­pers, is also an acquired taste.

Producers must bal­ance these pos­i­tive attrib­utes when craft­ing a high-qual­ity extra vir­gin olive oil to cre­ate the most fla­vor­ful oil pos­si­ble.

Along with the pos­i­tive attrib­utes, tast­ing pan­els also iden­tify the five most com­mon neg­a­tive ones listed by the IOC: frost­bit­ten, fusty, musty, ran­cid and winey. Any of these defects means that an olive oil can­not be graded as extra vir­gin.’


Frostbitten olives give the olive oil sam­ple the taste of wet wood. The defect occurs when the olive trees are dam­aged by frost.

Fustiness occurs when olives have been stored improp­erly after the har­vest and before milling, and begin to fer­ment. Fustiness can be detected both by taste and a muddy sen­ti­ment that forms at the bot­tom of the con­tainer.

Mustiness, which gives olive oil a humid or earthy taste, occurs when fungi or yeast grow on olives due to humid stor­age con­di­tions or if they have not been washed.

Rancidity is a fat gone bad.” It occurs when the oil is oxi­dized, which hap­pens with pro­longed expo­sure to air, heat or light, and nat­u­rally occurs over time. Rancid oils have a greasy mouth­feel and waxy, stale taste.

When olive oil becomes winey, it devel­ops a vine­gary, acidic or sour taste. The defect occurs when mill equip­ment is not prop­erly cleaned, and olive residue begins to fer­ment, form­ing acetic acid, ethanol and ethyl acetate.

How extra vir­gin olive oil is made

EVOO is extracted mechan­i­cally with­out the use of heat or chem­i­cal sol­vents.

The process begins in the olive groves. After daily tem­per­a­tures have cooled off, farm­ers har­vest their olives (by hand or mechan­i­cally) and imme­di­ately take the fruits to the mill.

Lower tem­per­a­tures dur­ing the har­vest help pre­serve the polyphe­nols in EVOO, so many farm­ers in hot­ter places opt to har­vest at night.

Once the olives arrive at the mill, the leaves are removed and they are washed.

See Also:Spanish Study Suggests More Effective Way to Transform Cold-Stored Olives

After the olives are washed, they are brought to the grinder. Most mod­ern mills use a blade, disc or ham­mer mill to grind the olives into a paste. Traditional mills still use stone mills, but these are less effi­cient.

After being crushed, the olive paste goes to the malaxer, where it is slowly stirred and the oil droplets accu­mu­late. This is the stage at which olive oil devel­ops its char­ac­ter­is­tic aro­mas and fla­vors.

From the malaxer, the paste is brought to the cen­trifuge to sep­a­rate the oil from the water and pomace – solid waste com­pris­ing stems and pits. Traditionally, this was done with a hydraulic press (hence the term cold-pressed).

After the first cen­trifug­ing, many mills opt to cen­trifuge the left­over oil once more to remove the last of the water and pomace par­ti­cles.

From here, the oil is poured out and is either taken to be fil­tered and/or stored in stain­less steel tanks under inert gas, which is non-reac­tive.

Provided the oil meets the afore­men­tioned chem­i­cal and organolep­tic stan­dards, it is graded as extra vir­gin.’

Why extra vir­gin olive oil is so healthy

The monoun­sat­u­rated fatty acids and bioac­tive com­pounds, such as polyphe­nols and vit­a­min E, con­fer a wide range of health ben­e­fits on extra vir­gin olive oils that are not present in other oils.

The over­whelm­ing major­ity of these health ben­e­fits come from the polyphe­nols in EVOO, which is why vir­gin olive oil and refined olive oil do not have the same health ben­e­fits.

See Also:Health News

Lowering the risk of car­dio­vas­cu­lar dis­ease and dia­betes, and pre­vent­ing can­cer, and a range of neu­rode­gen­er­a­tive dis­eases are the main health ben­e­fits of EVOO.

However, there are also plenty of oth­ers rang­ing from improved skin care and den­tal hygiene to a range of other dis­eases asso­ci­ated with inflam­ma­tion. Scientists in Spain are even using sup­ple­ments made from polyphe­nols found in EVOO in a trial to treat Covid-19.

These health ben­e­fit bona fides have been borne out over the past 60 years by thou­sands of peer-reviewed aca­d­e­mic stud­ies.

You should cook with extra vir­gin olive oil

Due to its healthy qual­i­ties and exquis­ite fla­vor pro­files, extra vir­gin olive oil should be an essen­tial ingre­di­ent in every cook’s kitchen. Plenty of Michelin-star chefs think so.

While most con­sumers are accus­tomed to dip­ping bread in or dress­ing sal­ads with extra vir­gin olive oil, there are plenty of other excel­lent culi­nary appli­ca­tions.

See Also:Cooking With Extra Virgin Olive Oil

EVOO’s high smoke point – up to 240 ºC (475 ºF) for short peri­ods and 180 ºC (355 ºF) for longer peri­ods – is excel­lent for bak­ing, grilling, sauteéing and fry­ing.

However, extra vir­gin olive oil is best known as a fin­ish­ing oil and an excel­lent option for mak­ing stews and soups.

While EVOO has proven to be an essen­tial ingre­di­ent in any cook’s pantry, it is impor­tant to note that not all EVOOs are cre­ated equally.

See Also:Olive Brine, a Secret Kitchen Ingredient

Depending on the dish, cooks should select a del­i­cate, medium or robust oil (mea­sured by fruiti­ness). While some recipes spec­ify the type of EVOO nec­es­sary, there are a few rules of thumb for pair­ing food and extra vir­gin olive oils.

  • Delicate extra vir­gin olive oils have the light­est fla­vors and are best for sautéing and bak­ing. They are also excel­lent for com­ple­ment­ing the sub­tle fla­vors of fish and poul­try.
  • Add a medium EVOO to soups and sal­ads with strong fla­vors for an extra kick.
  • A robust EVOO is great for adding fla­vor to soups, stews and red sauces. They are also great for fin­ish­ing grilled red meat dishes.

Where to buy extra vir­gin olive oil

Specialty food shops that deal directly with pro­duc­ers or importers are the best place to start when look­ing for extra vir­gin olive oil.

The retail finder on the Official Guide to the World’s Best Olive Oils makes it easy to find award-win­ning extra vir­gin olive oils near you or through online retail­ers.

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