Olive oil: The Do’s, the Don’ts, and the Varieties
Choosing olive oil at the supermarket can be a confusing exercise, there are far too many brands, too many varieties and “wait, which is the healthiest olive oil?”. This article uncovers the varieties, the types you need to avoid, and some surprising factors around the use of olive oil.
So first, what is olive oil? Olive oil is made from the fruit of the olive tree, which is naturally high in healthy fatty acids. There are several types of olive oil on the market today, including extra virgin olive oil, virgin olive oil and regular olive oil — but research shows that extra virgin olive oil benefits are more abundant than the other varieties.
The pressing or crushing of olive fruit produces olive oil. It comes in different grades, depending on the amount of processing involved. There are unrefined (virgin) grades and refined grades. The less the oil is refined by heat and chemical treatments, the higher the quality of the oil.
Virgin varieties of olive oil are believed to offer the greatest health benefits as they retain most of the nutrients from the olive fruit.
What are the main varieties of olive oil?
- Extra virgin olive oil: The premium grade of olive oil. Extra virgin olive oil is made from the first pressing of olives. The oil is extracted by the traditional cold-pressing method, where no chemicals and only a small amount of heat are applied. For olive oil to be extra virgin, the acidity level must be below 0.8 per cent. The acidity is affected by how many hours are left in-between picking the olives and taking them to the mill to be cold-pressed. The longer the olives wait around, they start to ferment and the acidity level increases, while the quality of the oil decreases. The cleanliness of the press is also a huge factor in the end result of the product.
- Virgin olive oil: This oil is produced from the second pressing of olives or from the second-best grade of olives by cold-pressing, after extra virgin is created. Virgin olive oil is still considered good quality as it is without the use of chemicals and uses little heat.
- Pure / Olive oil: This oil is generally labelled as ‘olive oil’, but can also be marketed as ‘pure’ olive oil. This type of oil is non-virgin, commercial-grade olive oil. It is ‘pure’ olive oil to the extent that it consists only of olive oil. This grade of olive oil consists of the inferior oil that is a result of subsequent pressings after the virgin oil has been extracted from lower-quality olives. This oil then undergoes a refining process involving heat, chemical solvents, high pressure and filtration treatments. This oil is then mixed with a small quantity of virgin olive oil to restore colour and flavour.
- Light / Extra light olive oil: These oils are produced from the last pressing of olives. They are more refined and of lower quality than the other grades. There is little of the natural olive flavour and colour in these oils as the oil is made with refined olive oil and sometimes other vegetable oils. This can suggest they’ve been chemically processed and are a mix of low quality oils. Don’t get confused by thinking Light or Extra olive oil has less fat or is better for your weight. It has nothing to do weight-related, only the quality of the oil. It is best to avoid this type of olive oil.
Olive oil: The DOs & the DON’Ts
Don’t store your olive oil like wine; Do use it once opened (and enjoy it)
If you buy expensive olive oil and ‘save’ them for special occasions, don’t. Splurging out a few tablespoons every few months will only see your expensive olive oil go bad. The time from tree to crush to fully produced oil must be as brief as possible. Once bottled, olive oil has an 18-24 month shelf life. Producers recommend using up the oil within 30 to 60 days upon opening.
Don’t buy giant sizes olive oil tins; Do buy small in small quantities
With most producers recommending consumption within 6-8 weeks when opened, buying your extra virgin olive oil in 4L drums will take you almost a year to use. Generally, this means greater oxygen exposure and consequently oxidation of the oil occurs, which causes off flavours in the olive oil. So if you can, buy in small quantities and use within 6-8 weeks. Alternatively, store it in smaller bottles to minimise its exposure to oxygen
Don’t add olive oil to cooking; Do use alternative oils for high temperature cooking
Olive oil is great for dressing salads and drizzling over meals but don’t cook with the popular product. If heated up beyond 80oC, olive oil starts to break down and become quite unhealthy. Unsaturated oils that can withstand high temperatures without breaking down such as vegetable, canola, safflower and rice bran oil are best for shallow and deep frying. Butter is also a bad choice as it takes a long time to melt but no time to ignite, so burns easily. Though experts do advise it’s ok to cook food in a little oil before adding a knob of butter near the end for colour, flavour and a glossy texture.
The key to healthy cooking with olive oil, and minimising damage, lies in keeping the temperature below the smoke point of the oil. That means keeping the heat below 160oC for EVOO, and below around 195oC for virgin olive oil (VOO). The EVOO smoke point is relatively low, but this is less of an issue when cooking vegetables which have a high-water content and so help lower the overall cooking temperature.
The best oils for high temperature cooking:
- Virgin coconut oil
- Avocado oil
- Ghee (clarified butter)
- Goose/duck fat
- Macadamia nut oil
- Rice bran oil (especially suitable for Asian-style stir frying)
Don’t leave your olive oil exposed to light or by the oven; Do keep it in a cool, dark place
It only takes a few days for your olive oil to deteriorate if left by a sunny window or hot oven. If you do this, opt for bottles of olive oil with dark glass, or simply store it in a cool, dark place. Ultraviolet rays can break down an olive oil over time where extended exposure to light can deteriorate the quantity and quality of the antioxidants found in olive oil. The optimal storage for olive oil is 15oC – 32oC. Exposure to warmer temperatures causes unpleasant flavours to develop in the olive oil.
Don’t judge olive oil by its colour; Do judge it by what is marked on the label
Olive oil shouldn’t be judged based on its texture or colour. High-quality olive oil comes in all textures and hues, depending on its harvest, olive type and filtration.
Don’t be fooled by ‘fake’ extra virgin olive oil; Do your research
The importance of getting the right kind of extra virgin olive oil cannot be overstated. It’s quite common for major grocery stores to shelve olive oils with ‘extra virgin’ on the label, but has in fact been diluted with other refined oils. Yes, surprisingly, store shelves are lined with fake olive oil products. Some reports even show that up to 70% – 80% of the extra virgin olive oil sold worldwide is watered down with other oils and enhancers. Some manufacturers claim this is to make the olive oil taste more flavorsome, however this type of modified olive oil can pose risks to your health. Australian consumers can be more confident of the quality of the extra virgin olive oil they are considering buying after Australian Competition and Consumer Commission intervention. In any case, it always good to do some research and make sure that you’re actually getting real extra virgin olive oil. If in doubt, The Australian Competition and Consumer Commission has a buying guide with information about olive oil categories and different product grades. It is available on the ACCC’s website – which you can view here.
Don’t just look at the “Best-by” date; Do also look for the “Harvest date”
When it comes to olive oil, fresh is best – but a harvest date is how you determine the freshness of a product; look for a date indicating the most recent harvest. The time from tree to crush to fully produced oil must be as brief as possible. Once bottled, olive oil has a shelf life of 18-24 months. If there’s no harvest date on the container, it’s quite possible people are trying to bottle oil that might be more than 2 years old. However, there are no mandates by any authority requiring the harvest date on the label, which means locating the harvest date can be hit-and-miss. What’s the difference between the two dates? Harvest date is when the olives were picked from the trees, whilst the best by date is a calculation by the producer and bottler of the olive oil as to how long the olive oil will last under good storage conditions. Small producers are more willing to be upfront about their harvest date because they tend to sell out of each season’s stock. In the meantime, we suggest you choose oils with a best-before date at least 12 months away, and avoid purchasing oils that are displayed under direct sunlight or in an overly warm environment.
Don’t get fooled by fancy marketing names; Do only buy extra virgin olive oil
‘Virgin’, ‘pure’, ‘fine’, ‘light’ and just plain old ‘olive oil’ are not worth consideration. These types of oil have been heavily refined into nothingness, a pale imitation to which some extra virgin oil is added for colour and flavour. Remember to check the oil’s acidity – to be extra virgin it must be under 0.8 per cent. The taste should be bitter, peppery and pungent but not musty or fusty. If in doubt, The Australian Competition and Consumer Commission has a buying guide with information about olive oil categories and different product grades. It is available on the ACCC’s website – which you can view here.
Read more on the importance of staying healthy over 60 in volume 2.
Volume two: Looking after your health and well-being after 60
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betterhealth.vic.gov.au. Olive oil. Read article
– Dr Axe. Olive Oil Benefits for Your Heart & Brain. Read article
– California Olive Ranch. The do’s & don’ts for storing olive oil to keep it fresh. 17 July 2011. Read article
– California Olive Ranch. What affects the quality of olive oil? Read article
– Courier Mail: Cooking: Kitchen dos and don’ts – By Belinda Seeney, October 10, 2016. Read article
– anhinternational.org. The do’s and don’ts of cooking with olive and other oils. 27 January 2016. Read article
– Authority Nutrition. 11 Proven Benefits of Olive Oil. 4 June 2017. Joe Leech. Read article
– Tree Hugger. 9 things you know about olive oil that are likely wrong. 18 May 2015. Breyer, M. Read article
– DailyMail. Can you tell if your olive oil is REALLY extra virgin? MailOnline visits Spain and discovers 80% of the industry is fraudulent. Jessica Satherley. 20 July 2016. Read article
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