cucina bene; mangia bene (enlightenment on evoo–part two)
Unfortunately as the demand for high quality olive oil increases worldwide and individual countries compete vigorously for each consumer’s purchasing dollars, the path to sourcing fine tasting olive oils full of beneficial health properties has become arduous at best. While standards exist today for classifying olive oil including both international and domestic ones, these standards are usually left up to the local countries or trade associations to enforce, or up to the local producer to honor through ethical business practices.
Due to this lack of enforcement and oversight, some unethical producers abusing the industry with mislabeled or adulterated products, and a mish mash of standards and certifications, it very easy to see why consumers are so confused about how to purchase olive oil. While these types of issues are not going away anytime soon, we can equip ourselves with knowledge to achieve our goal of buying quality products that enhance our own health and culinary experiences.
So let’s explore some things we do know about olive oil and how we can get the most out of this wonderful kitchen ingredient:
The four adverse forces impacting olive oil quality are age, air, light and heat. Unlike a fine wine, olive oil has a shelf life that is relatively short-lived. The shelf life can range from a few months like in the case of new harvest or new oil products (Olio Nuovo), or can extend up to two years for some types of premium EVOO. Even in a bottled state, the oil is slowly oxidizing over time. As the oil ages, it may start to lose some of its fruitiness and stability. As time moves on, the oil will start to exhibit defects of smell and taste, and then eventually it will turn rancid. Oil is especially susceptible to oxidative rancidity and therefore it is best to try to find the freshest oil whenever possible. Once opened, you should try to consume the olive oil quickly as well.
As mentioned above, the oxygen in air can have a deteriorating impact on olive oil. Therefore, producers are very cognizant of their techniques when handling olive oil throughout the milling and blending stages in order to minimize it to any harmful air exposures. As soon as the olives are removed from the tree, enzymes in the olives start the decomposition process necessitating the need to mill them right away. If the olives sit for over a day unprocessed, they can begin to heat up and ferment, or wet olives can begin to mold. These events can lead to the olive oil being bad right at pressing.
Throughout the milling and extraction process, oxidation is always a concern. With the traditional stone ground milling/woven mat process, the olive paste is exposed to the open air at different times and the mats used in the mechanical/hydraulic presses require constant attention towards cleanliness to avoid causing contamination. Some recent innovations have occurred using a vacuum based system where the olive paste is mixed in a malixer and moved to a decanter for separation, all sealed from the outside air.
As with more traditional approaches, the vertical or finishing centrifuge process is another important step to removing the water component from the olive juice, thereby reducing the oil’s exposure to any contamination caused by contact with the olive water. At the conclusion of the initial pressing, the oil is in a turbid state and is ready to be settled out for a few months of storage in a cool place. The oil is stored usually in stainless-steel tanks with inert gas in the head space to prevent any oxidation. Any solid particles or water remaining in the oil collect in the bottom of the storage tank and are removed to prevent any fermentation that could contaminate the oil as well.
The last two negative influences on olive oil quality are light and heat. Exposure to prolonged light or heat can cause the oil to oxidize creating off flavors or even rancidity. Many quality-minded producers will bottle their oils in dark bottles or in tin cans to minimize light exposure. Also, bottles can be wrapped in foil to minimize light exposure and additionally, some producers use boxes to store their oils throughout distribution to the end consumer to prevent any light and heat damage.
The International Olive Council (IOC) based in Madrid Spain has developed a set of standards adopted by many international countries and these standards often serve as a guidepost to classifying olive oil. In addition, other non-member IOC countries have adopted their own set of standards like Australia for example. Within the United States, there is a separate standard defined by the U.S. Department of Agriculture and even states like Oregon and California have legislated olive oil definitions. With so many standards existing today, it is understandable to see why the general consumer is confused.
Let’s take a look at the key aspects of the IOC standards and how they can help us in narrowing our choices for finding the right types of olive oil to consume:
1) Part of the classification deals with how the olive oil is produced and can be grouped broadly under three categories identified as ‘virgin’, ‘refined’ and ‘pomace olive oil’. To be considered ‘virgin’, the olive oil must be produced using physical means without any chemical treatments. ‘Refined’ oil means that chemical processes were used to extract the oil or to remove strong taste defects, or to neutralize the acid content. In effect, chemical processing techniques are used on the olive oil similar to the ones being used for refining seed or nut oils. ‘Pomace Olive Oil’ represents the small amount of oil extracted from the pomace (olive solids, pulp, pits, etc.) after the initial pressing of the olive fruit. The pomace oil is extracted based on the use of chemical solvents, and then later processed using high heat to refine the oil and to also remove the initial set of extraction solvents. Based on these classifications, I would recommend only sourcing virgin olive oils!
2) The IOC standards also identify classifications based on chemistry and flavor aspects. From a chemistry standpoint, the free oleic acidity level of olive oil is important. The lower the number, the better the quality of the olive oil. For flavor, the oil is judged by tasting panels to determine any defects in smell or taste, and to identify any positive qualities of the oil. The highest grade of olive oil is known as ‘Extra-virgin olive oil’ which possesses a low oleic acid level, no oil defects and superior tasting qualities. I recommend using only EVOO for both everyday uses like sautéing and frying, and as condiment oil for flavoring or finishing foods.
3) Within the standard, lower consumer grades include ‘virgin olive oil’, ‘pure olive oil’ and ‘olive oil’. The main differences involve larger oleic acidity levels and a greater number of tasting defects present in the oil. In general, these oils are cheaper but with it, the flavor components have been reduced and many of the health properties like the level of anti-oxidants contained within the oil have been lowered by the use of chemical or refining processes.
4) In some cases, a small amount of virgin oil has been blended with refined oil to create olive oil with a lighter taste profile. These products are sometimes marketed as ‘Light’ which really reflects ‘light in taste’ not in caloric content. Also, ‘pomace olive oil’ is marketed to the retail consumer and often includes a small amount of virgin oil blended with refined pomace olive oil. While less expensive to EVOO, the concern in using pomace olive oil is that the refining process can introduce harmful levels of polycyclic aromatic hydrocarbons (PAHs) like benzopyrene. I would not recommend using any of these types of olive oils.
Based on achieving the best health properties and great tasting foods, I recommend using EVOO only. For lighter flavor uses, you can choose a delicate style of EVOO possessing soft fruity qualities and very little bitterness or pungency. For sautéing or frying, a less expensive bulk style EVOO can do the work. And remember, EVOO tends to have higher levels of polyphenols (anti-oxidants) which are part of the motivation in adhering to the Mediterranean style diet.
Taking into account the four adverse forces, olive oil should be stored in a cool and dark place. For everyday use, a smaller container of olive oil can be stored in a kitchen cupboard conveniently accessible for cooking. In some cases, you may want to store a bulk size container in a basement setting, wine cellar or the garage for later access. Leaving olive oil out next to the stove is not recommended due to the proximity to the ill effects of heat and light.
Olive oil should be stored within a dark shaded bottle that has a tight fitting cap. When bulk sized cans or bottles reach half full, it is recommended to move the remaining oil into smaller containers thereby reducing oxidation. Also, refrigeration and freezing of olive oil is not recommended due to reduced shelf life concerns and a higher chance of contamination from condensation.
Another option is to store olive oil in a fusti for dispensing the oil on an ‘as needed’ basis. This can be an economical way to buy bulk quantities of olive oil and keep it fresh for many months of kitchen use. A fusti is usually made of stainless-steel and has a tight fitting cap that can be screwed down to seal it. A fusti is equipped with handles near the top for moving it around efficiently and a spigot for dispensing the oil. A fusti can be placed on a flat counter or a shelf, and can also be ordered with a stand. Finally, a fusti can be cleaned easily and reused for the next seasonal batch of olive oil.
Some olive oil merchants sell the fusti empty allowing you to add your own olive oil selection. In other cases, you can order the fusti already filled with olive oil, and in some cases, the merchant can add inert gas before sealing it to further minimize oxidation. Most of the resource sites I visited feature different sizes of fusti made in Italy.
In my next post, we will explore more details on how to shop for EVOO whether at a supermarket, specialty food store or online. Also, we will review labeling information which can help us in our search for sourcing the right olive oil product. Bruce-