Olive Oil #ScienceSundays

How much do you know about olive oil? There are many factors that go into its classifications and uses in the kitchen.

It’s pretty obvious based on the variety of olive oils available at the store that not all are created equal (and not just the price ranges). I had always heard to save the extra virgin for dressings/finishing and use light/regular olive oil for cooking due to its higher smoking point. The smoking point is literally the temperature at which it begins to smoke and can result in burnt tasting food.

Below are the smoke points for three types of olive oil [1]:

• Extra virgin – 325-410°F / 165-190°C
• Virgin – 391°F / 199°C
• Light (pure or “regular”) – 465°F / 240°C

Smoking points are particularly important when frying food (also searing and stir frying) and for such applications it is recommended to use an oil with a smoking point above 400 F [1,2]. Take into consideration however that smoking points are determined by heating the oil by itself in a contained environment [2], something you probably are not going to do since you are adding things to that pan. So when sautéing, which is at lower temperature cook, you don’t need an oil with a higher smoke point [1]. I will admit that while you can cook with extra-virgin olive oil, I typically save the pricey, high quality stuff for cold applications and use the less expensive stuff for cooking and baking.

However, if you are like me and sometimes get distracted and turn around several minutes later to find a smoking pan of oil, using the light (“regular”) olive oil with the higher smoke point isn’t a bad idea. As I mentioned above, you’re not going to want to cook in that oil even if you can get it to stop smoking because your food will end up tasting smokey in a burnt way, not the good smoked meat kind of way.

Here’s another thing I’ve been told – you should not use the same oil more than twice. Why? Heating oil produces more free fatty acid (FFA) which aligns with a decrease in the smoking point [2]. Since extra virgin olive oil is not refined, the FFA can range can vary which is why the smoking point of this oil has a range of temperatures. Meanwhile, light olive oil is refined with very low FFA providing more consistently higher smoking points [4].

But refined sounds better than it is. Refined olive oils are treated with chemicals or altered by temperature, resulting in little or no olive aroma, flavor, or color [5]. Meanwhile, extra virgin olive oil retains more true olive taste, along with the natural vitamins and minerals found in olives, making it the highest quality you can buy. In fact there are specific standards to receive the “extra virgin” label because olive oils can vary drastically in taste and quality.

Which brings me to how olive oil is graded. It is the amount of free oleic acid that indicates how much fat has broken down into fatty acid, and thus they can be graded based on level of acidity [5]. Currently, to be classified as extra virgin the oleic acid threshold is 0.8% (regular olive oils range from 3-4%). But Unaprol, a consortium of Italian olive oil producers, has presented a proposal to reduce the oleic acidity threshold to 0.5% in order for an olive oil to be classified as extra virgin [6]. The reason behind this push is that the current threshold allows too many average oils to achieve the industry’s gold standard and undermines consumer confidence in the standard.

Despite what seems like a decent amount of industry standardization, there is still an amount of fraud in the industry (honey has this problem too which I will address in another post). Professor Lourdes Arce of the University of Cordoba demonstrates that chemical markers can correctly predict sensory characteristics of olive oil. He has a model which delivers >90% correlation between the oil’s aromatic fraction (measured using gas chromatography and ion mobility spectrometry) and the judgement of a panel of expert tasters [7]. These findings could results in less expensive, objective, and reproducible measures of olive oil quality and thus reduce fraud.

So what did we learn? Not all olive oils are created equal. Refined regular olive oil is a good all-purpose cooking oil, but if you want that true olive flavor look for extra virgin with lower oleic acid – just don’t deep fry with it.

If you’d like to try Pomora olive oil, you do so by actually adopt olive oil trees in Italy, which helps sustainable family farmers continue to do what they do. When you adopt, you receive quarterly deliveries of Italian olive oil that actually came from your tree, sending both classic and flavored varieties. Get 25% off with code SPIFFY25!

References:

1. https://www.seriouseats.com/2014/05/cooking-fats-101-whats-a-smoke-point-and-why-does-it-matter.html
2. https://www.thespruceeats.com/smoking-points-of-fats-and-oils-1328753
3. https://health.usnews.com/wellness/food/articles/why-you-should-stop-worrying-about-olive-oils-smoke-points
4. https://www.aboutoliveoil.org/olive-oil-smoke-point
5. https://www.thekitchn.com/whats-the-difference-between-olive-oil-and-extra-virgin-olive-oil-word-of-mouth-218767
6. https://www.oliveoiltimes.com/olive-oil-business/italian-trade-group-proposes-new-classification-for-extra-virgin-olive-oil/67107
7. https://www.uco.es/investigacion/ucci/es/noticias-ingles/item/2518-the-university-of-cordoba-has-simplified-the-method-to-categorize-olive-oil

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