I opened a small bottle of extra virgin olive oil, which I recently purchased, and it tasted very bitter – very disappointing. Nor can you tell from its colour (photo of three samples of extra virgin olive oils in my pantry), and this is the point, you can never ascertain how good it is going to be until you taste it.
I also find that there is confusion about types of olive oil. For example many of those people who buy ‘light’ oil think that this oil is lighter in calories – this is not the case.
Olive oil is essentially a fruit juice and like any good fruit juice, it tastes best when it’s fresh and the fruit is ripe and in good condition.
Unlike wine, olive oil doesn’t really mature or improve with age, although a couple of months after it’s been pressed and bottled, the oil may “open up”, drop its veil of sediment and become a little more aromatic.
The other important thing to remember about olive oil is that while it can be called a juice it is also a fat and will oxidise if it is exposed to too much heat, air and sunlight. Oxidised oil tastes rancid, so it is best to keep your oils in a cool, dark place.
Olive oils differ in quality, colour, flavour and aroma.I use olive oil for all my cooking and lots of it, but I don’t use expensive, high quality oil for frying or cooking, because the flavours of the ingredients would overpower the taste and fragrance of the oil. Rather I choose different oils for different purposes, saving my best oils to complement the flavours of ingredients, especially those I serve raw, so the taste of the oil can be appreciated.
In all my recipes I always use extra virgin olive oil.
Looking beyond the obvious sexual allusions, the description of an olive oil as “pure”, “virgin” and “extra virgin” really does raise the question about which oils are which?
In simple terms extra virgin olive oil is the finest and fruitiest of oils. In recent years the objective qualities for grading olive oil have been developed by the International Olive Oil Commission (IOOC)
According to the IOOC criteria, to be classified as extra virgin, an oil has to be free of impurities, with no flaws in flavour or aroma, and be produced at temperatures below 28 degrees Celsius. Extra virgin the oil must also have a free fatty acid content below 1 per cent.
Why are temperature and acidity important? Both are indicators of quality. A low percentage of free fatty acid is a sign that the oil comes from sound, fresh, ripe fruit. Extracting oil at higher temperatures, accelerates the breakdown of the beneficial anti-oxidant compounds in the oil, reducing the oils natural protection against oxidation. Higher temperatures also evaporate some of the more volatile aromatic flavours of the oil, robbing it of its more complex and subtle fragrances.
Virgin olive is next in the rankings. This oil must also be free of flaws in flavour and aroma, but has a higher free fatty acid content of between 1 and 2 percent.
Pure olive oil rates lowest, although it should still have an acceptable flavour and aroma without flaws and an oleic acidity below 3.3 percent.
But rather than being produced by a centrifuge or a pressing method, pure olive oil is more likely to have been produced by the treating the oil with solvents such as caustic soda through a process known as “”, which in effect turns the oil into soap before it is dissolved, distilled and re-constituted which involves extremely high temperatures.
These days, especially in Australia and increasingly in Europe, olive oil is being produced and marketed in accordance with standards set down by the IOOC.
The IOOC is also a vigorous advocate of truth in labelling.
Most virgin and extra virgin olive oils are also labelled on the bottle as “first, cold pressed”.
The way most oils, and that includes quality extra virgin oils, are produced these days, “first, cold pressed” is a meaningless marketing phrase, that harks back to another time when olives were crushed to a paste that was then spread on mats which were stacked in layers and pressed.
Under that system, after the pressing had produced as much oil as possible, the paste and mats were doused in hot water to release any oil still in the paste and extract the very last of the drops from a second or even a third pressing.
These days, such a method is too labour intensive and too slow for commercial olive oil production. Now producers tend to rely on continuous centrifugal extraction machines where the olives are poured in one end, milled to a paste, pressed under centrifugal force, and then separated into oil and water, leaving a dried pulp to be disposed of later.
The temperature of these continuous presses can be regulated easily and the best results are obtained at around 28 degrees celsius, a comfortable room temperature, that is anything but cold, but promotes oil flow and doesn’t evaporate the aromatic flavours of the oil.
My advice is to always put a new oil to the taste test. It should certainly not taste rancid, metallic or have a slack, fatty flavour. A good oil should be fruity and balanced, with a hint of peppery bite on the back of the throat.
The bulk of the oil I buy is in 3 or 4 litre tins and it is labelled Extra Virgin Olive Oil. I use this oil every day in all my cooking, to braise, bake, fry, marinate, and sauté; for preserving and pickling, and even to oil my baking tins. This is the oil I use when I don’t want the flavour to dominate the other ingredients.
I also buy a variety of quality extra virgin olive oils that come in bottles. These oils are much more expensive than the oil I buy in bulk tins. A fine 375ml bottle may cost as much as or more than a 4 litre tin, because the flavour is stronger and fruitier and greater care may have been taken with picking and processing the fruit. These are my best oils. I save these for salads and other cold dishes or to trickle over bread or hot dishes just before serving so the rich flavour can be fully appreciated.
There is so much good olive oil now produced in Australia.