How to Choose Extra Virgin and Virgin Olive Oil
What is Olive Oil?
Olive oil is made by pressing olives. Essentially, it is olive juice.
What About Quality?
Cold pressing gives better quality olive oils with more complexity of aromas and polyphenols. Not really “cold”, but with temperatures that have not exceeded 28oC.
Quality is assessed by the chemical and the organoleptic (aromas and taste) characteristics of the olive oil.
Chemical Characteristics are free acidity (which must be under 0,8 for extra virgin olive oil, and under 2 for virgin olive oil), and oxidation (up to 20 for extra virgin olive oil).
Colour is not a safe quality criterion. The greener oils are made of younger olives with more chlorophyl and the more yellow/golden olive oils are made of riper olives, higher in carotene. If the olives are overripe the colour is greyish/brown (this oil will probably not taste fresh and clean).
What Does it Taste Like?
The aromas and taste (organoleptic characteristics) of extra virgin olive oil should be fresh, fruity (like fresh olives), and clean (free of defects). Virgin olive oil is of a lesser grade and has been judged to have sensory defects (this is what most people consume, whether they are aware of it, or not).
Aromas and taste characteristics are categorized as fruity, sweet, bitter, pungent (spicy).
Different varieties of olives, grown in different areas, at different altitudes, different microclimatic conditions, will give olive oils with different taste profiles.
Some varieties are sweeter tasting and others are more bitter and pungent. Also the greener the olive is harvested, the more it will be bitter and pungent (and less aromatic).
The spice is a kind of burning sensation that goes from the back of your tongue, throat to your nostrils, the way horseradish would do (obviously not as intense). Bitterness is associated to the polyphenols found in a variety. Koroneiki, in Greece, is rather bitter tasting. Manaki is rather sweet and “buttery”.
Can it Taste Unpleasant?
Rancid, fusty, musty and vinegary are the most common unpleasant aromas and tastes, with the first two being the most commonly encountered.
If your throat is left with a rather greasy, burning taste, which is quite unpleasant, then you have rancidity.
Fusty is caused by anaerobic fermentation when olives wait in the mill for days, piled in sacks on top of each other. Hard to describe. If you’ve ever eaten a bruised, soft olive, that looks off colour, it probably tasted fusty.
Musty tastes mouldy, earthy and Vinegary tastes like vinegar.
Olives that have been struck by disease will give oil which doesn’t taste clean.
What about Production?
Olives need not only to be grown properly and to be disease free, but must also be harvested at the right time.
Just like grapes for winemaking, it is important to harvest at exactly the right time, so that the fruit both has its polyphenols and has had time to develop its “fruit” aromas. This will make the oil more complex and interesting.
The harvested olives must be kept and transferred properly, and pressed the soonest possible.
How to Store
Olive oil needs to be stored in the right way. It should avoid light, oxygen, high temperatures and moisture. Dark, cool and dry are the optimal storage conditions.
In Greece they say: “Age your wine, consume your olive oil within the year”. Well, that’s about right. If all is well, and the oil has been produced, harvested and pressed correctly, transferred and stored correctly, it is best used within 12 (-18) months of pressing.
It’s more “classy” and helpful when producers mention the date of production and lot number on the label of their products (that way you know what you are buying).
When the oil is freshly pressed, not filtered, it is slightly hazy and needs to be consumed very fresh (in the first one or two months). If you want to keep it the 12-18 months, filtering will preserve the taste characteristics better.
Even the best olive oil will become rancid if it is kept too long. It’s not bad for you, it just doesn’t taste very good.
Learn to Taste
As with everything, personal taste needs to be acquired. Some prefer more bitter and pungent oils, others sweeter and softer tasting oils.
You build your taste preferences and learn to distinguish quality if you keep tasting! Always taste two or three different oil samples. This will train your senses. Comparison helps.
Hint: “Light” olive oils are vegetable oils that contain a small percentage of olive oil (nothing to do with caloric value) and Refined olive oils are lesser, faulty, olive oils which have been cleared of their faults through certain processes. Nothing wrong with them, but….once you’ve had the ‘real’ stuff, you will never go back. No comparison; at any level.