Organoleptic attributes refer to the flavor and aroma and are detected by specially trained tasters.
These attributes (taste and smell), combined with the color of olive oil are the three sample constants that are used internationally to evaluate and rank the quality of the product.
The liquidity and the harmonious-balanced relationship of the attributes of olive oil contribute to the final assessment of its quality.
An experienced taster detects the attributes of olive oil starting to observe the color. The color may manifest the approximate degree of ripeness of the olives before the harvest, the way of pressing, receipt of olive way and others.
The color of olive oil may vary from dark green to gold, with many intermediate and other nuances.
This depends on the substances that dominate and are due largely to the olives from which the oil is produced. If chlorophyll prevails, the oil color is green or, for better, it has shades of green color.
If the carotenes dominate, the shades are aureus.
The olives, if in general are gathered at the beginning of the harvest season, give green color, due to the large amounts of chlorophyll they contain. If gathered ripe, the carotenes will dominate in the olive oil. Both the green and the aureus olive oil may be of very good quality. Cloudy olive oil may be very fresh that has not settled yet.
The emergence of aromas reminiscent of fruit or smell oil that just came out from the oil mill particularly valued and considered virtues. Like wine, the Tasters try to detect odors gladly accepted and are reminiscent of other products (e.g. fruits, such as apple, nuts, etc.)
The bitter taste of olive oil suggests the fruit gathered before mature (unripe). The bitter flavor intensifies much more if olive leaves remain in olives and are milled (being mashed) together.
The fruit flavor reveals ripe olives and balanced attributes. It is purely a matter of experience and knowledge to distinguish the flavors of olive oil.
The unpleasant odors are a major disadvantage of the oil.
Products with unpleasant smell should generally be avoided. Such odours (and flavors) may be mould, earthy etc.
The pleasant smell and taste indicate particular features which may be due to the area in which the olive trees are cultivated and the cultivation methods as well.
The tasting shows even if the product has been properly maintained and if its attributes have been retained. Generally, the olive oil produced by bland and modern technology without high temperatures presents exceptional features
The degree of acidity of the olive oil indicates the product content in oleic acid.
Generally, edible oil is considered, based on the directives of the International Olive Council, the one with acidity not exceeding 3.3 degrees (3.3%).
In Greek olive oil producing areas, good oil is that with acidity not exceeding 0.5% in oleic acid content (0.5 degrees).
Olive oil with increased acidity makes ‘perceptible’ its presence in the oral cavity, imparts a particular ‘nipping’ aftertaste and renders it not to be so pleasing.
The way of harvesting, storage and elision, may affect the degree of acidity.
Organic oil producers tend to establish the transfer of the harvest to the mill not with sandbags but with crates, where the harvest is not pressed and not injured.
Also, pure virgin olive oil producers take care not to store the olives over a couple of days to avoid deterioration of the product.
Oxidation (rancidity) can cause significant damage to the olive oil. Storage conditions (light, oxygen etc.) help the oxidation.
It is very easy for the taste expert to detect oxidation, even without laboratory examination, since it leaves a peculiar nasty (and very annoying, depending on the degree of oxidation) odour.
In general the oxidation can be an irrefutable witness of various lesions suffered by the olives and olive oil.