The all-time top 10 myths surrounding extra virgin olive oil
admin | March 10, 2010I give my top 10 myths surrounding Extra Virgin Olive Oil ……
Myth No. 1 – Extra virgin olive oil is made from the first cold pressing of olives.
Can be, but doesn’t have to be!
Extra virgin olive oil (EVOO) is officially defined as the oil extracted from fresh olives using a mechanical process without the use of excessive heat, additives or solvents.
“Mechanical” is the key word here. Most EVOO’s that are made in commercial relevant quantities are not made by pressing but by centrifugation whereby the lighter olive oil is spun away from the heavier components of the olive such as water and pulp. Still mechanical, still EVOO.
A centrifuge used to separate EVOO from olive water and olive flesh, stone and skin.
Myth No. 2 – Refined olive oil such as pure and light olive oil is made from the second pressings of the olive.
If you don’t press, then you can’t second press!
Refined olive oils usually start their lives as very poor quality olives which typically have fermented to some degree prior to being processed. The extraction process that is used to pull the oil out of these poor quality olives is the same as that which is used to produced good quality EVOO. But the end result is an oil that tastes so bad that it needs further radical processing to render it edible. The process is called refining and amongst other things it removes all the flavour from the oil –both the good the bad and the ugly. The final result is a bland product that is sold under the names ‘pure’, ‘light’ and ‘olive oil’.
Myth No. 3 – When making EVOO, the olives are crushed using heavy mill stones.
Very romantic but the days of granite crushing stones powered by donkeys is pretty well gone. Stone milling is very slow and the resulting olive paste is subject to oxidation. Today, most of the olives that are destined to become EVOO are crushed using motor driven means, the most common being the hammer mill. The hammer mill consists of an outer stainless steel screen and an inner rotating arm powered by a high speed electric motor. The olives are squished between the screen and the rotating arm resulting in a relatively oxygen free paste.
Donkey replacement – A hammer mill showing the perforated screen and rotating arm.
Myth No. 4 – Extra virgin olive oil that is made by pressing is better than those made using a centrifuge.
A few years ago some scientific research was published that suggested that this was the case. However, there are two types of centrifuge – the early model (early 1970’s) 3 phase and the late (mid 80’s) model 2 phase. This research compared pressing with oils from 3 phase centrifuges. For a 3 phase to work, water must be added to the olive paste prior to the oil being extracted. The addition of water causes some of the healthy polyphenols and flavour to be lost from the oil. However 2 phase centrifuges work without the need for adding water so EVOO’s made using these systems have the same or more healthful polyphenols and flavour as do oils made using a traditional press.
The big advantage of either centrifugal system over pressing is that it is much easier to keep a centrifuge clean. The mats used in pressing can be quite absorbent (there are a number of different types) and tend to hold oil which can inadvertently taint forthcoming batches of olives. Centrifuges can be more easily maintained to spotless standards. The bottom line is that in general EVOO’s made with centrifuges are more consistent than those that are made using your average press.
Also when you think about it, there is nothing inherently special about a press except that they have been used for a long time – but so has the wheel –and I don’t see too many Model T Fords on the road any more.
Myth No. 5 – Extra virgin olive oil made using a press is healthier for you than those made with a centrifuge.
Quite the contrary. The process of centrifugation is by nature, a rapid and enclosed process that protects the oil from oxygen during the separation process. This means that the naturally occurring antioxidants in the oil are conserved and end up in the bottle. If you expose the health giving antioxidants in olive oil to oxygen before they are bottled, then they by definition are used up. Better to have them in the bottle so they can help you stay healthy.
Myth No. 6 – Extra virgin olive oil that is clear has been filtered.
Well it might be but it probably hasn’t. If you leave a cloudy olive oil in a tank for even a relatively short time, the grungy bits will naturally settle to the bottom under gravity. Decant the clear oil off the grungy bit and whollah… clear oil ready for bottling. How gorgeously natural is that. Filtering oil is a tedious and messy business. Why bother mucking about with filters when you can let gravity do the work.
Myth No. 7 – You can’t refrigerate extra virgin olive oil
Refrigeration is a very effective way of prolonging the shelf life of EVOO. While some oils may partially solidify due to the oil containing naturally occurring levels of saturated fats and/or waxes, they will return to their normal state when they warm to room temperature. The aroma and flavour of the olive oil should not be affected in any way by refrigeration.
One small word of warning. There is some evidence that multiple thaws of oils can slightly shorten its shelf life. So if you use little bits and pieces very frequently then it is a better option to find the coolest dark place where the oil doesn’t solidify (say 10-12C) and leave it there.
Myth No. 8 – You can’t cook with extra virgin olive oil.
Good quality extra virgin olive oil smokes at a higher temperature than poor quality EVOO. In fact the smoke point of good quality EVOO is quite respectable and as such they can be used for shallow frying without any hassles at all. You can even get away with deeper frying with a little care (most foods will deep fry at temperatures below the smoke point of good EVOO), but realistically the economics of deep frying with good quality EVOO is pretty questionable given their premium price compared with other oils.
Myth No. 9 – Cloudy extra virgin olive oil is more healthy for you than clear EVOO.
There is absolutely no evidence for this. Most clear EVOO’s get that way by natural settling under gravity and not by further processing. So why wouldn’t they?
Myth No. 10 – The greener the oil the better it is for you.
For some, green just shouts freshness. But like many things EVOO, it’s not always what it seems.
For some varieties, green oil means that the olives were picked when they were pretty unripe and at a time when they were full of healthy polyphenols – hence the myth.
However, this pretty basic rule doesn’t always hold. Some varieties like Koroneiki and Verdale tend to make greenish oils regardless of their polyphenols level. Cool climates also tend to favour the production of the green pigment chlorophyll, so oils with the same colour but grown under different climatic conditions can have very different compositions.
Look at the oils labeled A-D below. These were sampled from a recent Australian EVOO competition. The oil on the far right, while being nearly an opaque emerald green had only a moderate amount of polyphenols (170mg/kg). It was a Verdale oil from the very cold marginal olive growing climate of Tasmania. The second from the left came in at a massive 620mg/kg of polyphenols. The colour definitely belied what was actually in the oil. Lots of golden coloured EVOO’s have very high polyphenols and are pristinely fresh. So in short don’t get too tied up with the colour of EVOO.
But then again if green is your favourite colour then go for it. I must admit that it always looks great on the plate….
Bravo! Very interesting, especially the explanation of color. I wonder what the oil was with such an extremely high polyphenol count and how it tasted.
It was an early harvest oil made from the variety Nevadillo Blanco. Southern highlands of New South Wales, Australia from memory. It tasted very bitter, but it had tons of flavour so it certainly had its place in the kitchen.