In ancient Greece, olive oil was not only used for consumption and cooking, but also in medicine and cosmetics. Homer referred to olive oil as “liquid gold” and Hippocrates called it “the greatest healer”, prescribed for 60 medical conditions. In our modern life, olive oils (« OO ») production is regulated, but it’s still one of top 3 products (along with meat products) that usually doesn’t comply with standards. Forbes stressed that probably 80% of italian extra virgin olive oil market is fraudulent or mixed with cheap refined oils. In Brazil, the Ministry of Agriculture reported 60% of olive oils labels were misleading with some brands found to be 85% of soybean oil. In the UK, the Rural Payment Agency carried out tests from more than 150 samples of olive oil during 2015 and 2016 and found that a third was not compliant with one or more standard requirements.
The quality regulation sets strict chemical and organoleptic standards. For example, OO must not be adulterated with any other type of oil, must pass a sensory analysis by a certified panel of tasters, and must meet analytical criteria.
Quality assessment of OO includes many requirements, but the most important are natural acidity level (the amount of free fatty acids expressed as % of oleic acid), peroxide value and organoleptic sensory scores (taste, smell). Acidity level is aimed to measure the quality of raw fruits that might also be affected by storage techniques. Peroxide value measures the oxidation status and indicates the damage that may have suffered natural antioxidants such as tocopherols and polyphenols.
Extra Virgin Olive Oil (the highest quality):
This category of Olive Oils must be obtained through a first extraction and pressing by mechanical means at less than 27º from fresh and healthy fruits. So no chemicals or heat added. The natural acidity may not exceed 0.8% and the peroxide index may not exceed 20 meq/kg. Note that the degree of acidity also depends on the variety of olive and the composition of the soil in which the olive trees grow.
Virgin Olive Oil (lower quality):
same as above, but the natural acidity may not exceed 2.0%. This higher acidity can be caused by many factors. The fruits may not have been that healthy or had been badly stored between picking and milling. The moment the olive is taken from the tree it begins to oxidize and degrade rapidly, and if fruits are left sitting for a few days or weeks, the quality of oil will suffer. It’s important that the time between harvesting and milling remains very short in order to retain the organoleptic properties of the oil and ensure zero defects. But it’s not unusual that the amount of olive fruits, especially harvested with machines, may exceed milling capacity. In this case, fruits need to be stored, and that’s when they may develop all kinds of degenerative processes.
Virgin Olive Oil will show slight defects of odour and taste.
Refined Olive Oil (low quality) or formerly called Pure Olive Oil:
This type of olive oil is produced in a refinery using chemical and physical filters as well as neutralization, bleaching and deodorization techniques. The end product is odorless, colorless and tasteless, devoid of any vitamins or anti-oxidants and its acidity artificially set at < 0.3%, but physically it is still olive oil. In this form it is sold to fish canneries for conservation of sardines, mackerel, squid, anchovies, etc., but the major part by far is mixed with typically 15% Extra Virgin Olive Oil or Virgin Olive Oil and sold to industrial users, professional kitchens and supermarkets at a discount for baking and frying.
Olive oils — made of refined OO and virgin olive oils: These are obtained by blending refined olive oil with virgin olive oil.
There are also other categories, but not all categories can be sold to consumers; only extra-virgin olive oil, virgin olive oil, olive oil composed of refined olive oil and virgin olive oils and olive pomace oil (lowest grade) can be purchased directly at retail level.
OO is not like wine, it doesn’t like aging! It’s perishable and is better when fresh. It should be consumed within 12 months from production, because polyphenol content, antioxidants, flavor, and aroma will decline over time, while undesirable rancidity and free radicals develop. So it’s paramount to pay attention to the label.
Unfiltered olive oil is not necessarily more genuine and healthy than filtered olive oil.
The olive oil obtained at the end of the extraction process is a product rich in particles of olives — pulp and stone. If not filtered, these tiny pieces initially induce a slight increase of nutritional content, which is great! But the shelf life of unfiltered olive oil is shorter because these particles will sediment on the bottom and accelerate the oxidation.
Key Factors for choosing olive oils:
1. Go for Extra virgin oil, don’t bother with anything labeled “virgin,” “light,” “pure,” or just “olive oil”.
2. Remember olive oil doesn’t like heat, light and air. The best packaging for extra virgin olive oil is a dark glass bottle (glass does not alter the taste of the product and is recyclable) or a stainless steel container that protects it from light. Some producers may also choose light bottles, but they should be put into boxes to preserve quality.
3. Store your olive oil in a dark place, it should not be sitting out in the kitchen where the sun can shine on it. By the way, stay away from olive oils kept on tables in outdoor restaurants.
4. Check “best by” or “pressed on” or “harvest day”. If there is no production day or “best by” day on the bottle , don’t buy it. “Bottled on” also does not mean much, it could’ve been in a tank for a year before it was bottled. No date means risking purchasing an olive oil that’s less than fresh and remember the shelf life of olive oil is 12 months. Some sources mention 18 months when stored in optimal conditions.
5. Look for certification seals. There are three types of EU quality seals:
* PDO, or the “Protected Designation of Origin” to ensure the quality of that region’s agricultural products, and which are subjected to more strict controls.
* PGI, or the “Protected Geographical Indication”.
* Organic Olive Oil, which guarantees ecological, chemical- and GM-free production
In the USA, the Californian Olive Oil Council (COOC) provides olive oil grade certification, which is based on even stricter rules than international standards. Chemical analysis involves an assessment of the oils level of free fatty acids, which must be no more than 0.5%, with a peroxide value of 15 meq 02/kg or less.
6. Cheap is a red flag, but expensive or fancy packaging wouldn’t guarantee the quality. For those looking to spend a fortune – λ /lambda/ Ultra Premium Extra Virgin Olive Oil (500 ml) Bespoke White Gold Plated Edition, favoured by celebrities, will cost you 11,000 euros. 🙂
7. Unfiltered olive oil is excellent if fresh and consumed quickly. But filtering is important to maintain stability and preserve the healthy qualities.