The oil tasting allows to determine the organoleptic properties of the product through the senses. By smell and taste, a qualitative assessment of their sensory characteristics is established. A group of specialized and trained tasters form a tasting panel, exercise the art of tasting to detect positive and negative attributes of oil, extract aromas and basic flavors according to the current rules, regulated by the International Olive Oil Council (IOC).
Although the score has a subjective component because it is based on the perceptions of tasters, the IOC set a series of conditions to ensure the greatest possible objectivity. The distribution of the tasting room, the shape of the glasses, the method and the requirements to be met by tasters are regulated in order to ensure impartial analysis.
Tasting room. It should have a comfortable and standard environment which helps to work and improve the reproducibility of results. All the elements are arranged so as not to distract the attention of the people. The tasters carry out their work in isolated tasting booths that promote concentration. The room to prepare and clean samples, the open panel, the office or waiting room are other spaces that are in the tasting room.
Tasting glass. The oil tasting requires the use of a specific glass, consisting of a glass and a watch glass. The cup is made out of resistant and dark glass to hide the color so the taster cannot condition the assessment. As a standard dimension of 7 cm. at the widest part and 6 cm. high, the cup fits in the hand to manipulate and heat the oil that it contains. The glass is placed on top of the tasting glass, which is narrower than the rest, in order to prevent odors from escaping when heating the oil.
Requirements and qualities of the tasters. They are trained with accredited knowledge to objectively quantify their sensory impressions. Their purpose is to identify and quantify the perceived stimulus. Prior to the oil tasting, they must meet certain standards of behavior:
- Do not eat any food one-hour prior to the tasting.
- Do not smoke one-hour prior to the tasting.
- Do not use any perfume, cosmetics or soaps which scent can alter the tasting.
- If the smell or taste of the taster can be affected or are under any psychological effects, the taste session must be cancelled.
Method. An accredited tasting panel consists of a minimum of 8 and a maximum of 12 people, among which is the head of the panel. This person is responsible for preparing the oil samples and placing members in different booths.
Once they are located as quietly as possible, the tasters begin the activity. In front of them, the oils are lined up in their tasting glasses each with a watch glass on them, waiting to be assessed. Each cup contains 15 ml. of oil and is encoded to not know which oil it is.
The first step is to heat the glass with your hands, keeping it covered with the watch glass and dunking it as much as possible in the inner wall, until the oil reaches a temperature of 28 degrees. When heated, the taster separates the watch glass and smells the sample using slow and deep breaths to extract the aromas. The smelling period should not exceed 30 seconds. After this, they take a sip, about 3 ml., and they distribute the oil throughout the oral cavity in order to extract the flavors.
Between the two oil tastings, it is mandatory to ingest a product that can eliminate the remains in the mouth of the product tasted first. The waiting time between the valuation of two oils should not be less than 15 minutes. It is not recommended to taste more than three samples a day.
Tasters write their results on a profile sheet. Later they share their conclusions in the open panel.
Attributes. Assessing the organoleptic properties of an oil, the taster establishes the intensity of positive and negative attributes on a profile sheet.
- Fruity. Group of features coming from the smell depending on the type of olives used. It is the result of using healthy and fresh fruit, green or ripe, during the making process. The fruity flavor is perceived directly and/or via the nose.
- Bitter. Typical flavor with oil obtained from green olives or olives that start to be ripe.
- Spicy. It feels spicy when it is touched. It is typical from oils obtained at the beginning of the season, mainly from green olives.
- Fusty or muddy. Typical flavours obtained from olives that have been stacked on top of each other or stored in bad conditions so they suffer advanced grade of anaerobic fermentation.
- Mould or humidity. Characteristic oil flavour obtained from olives which have developed fungi and yeasts due to being stacked and stored in humid conditions for several days.
- Stale. Flavour of some oils that have suffered intensive process of oxidation.
- Metal. These flavours taste of metals. It occurs when the oil has been in contact during a long time with metallic surfaces during the crushing, mixing, pressing or storage phases.
- Others. Iced, cooked or burnt, hay or wood, lubricant, vegetable water, brine, esparto, soil, worm, cucumber.