Sensory analysis such as the Swirl, Sniff, Sip and Swallow test is an essential technique to characterise food but how do you consistently describe what you are tasting across a range of oils?
To solve this, the International Olive Oil Council (IOOC) created a framework to evaluate virgin olive oils known as the “COI Panel test”.
This test uses a panel of between 8 and 12 expert olive oil tasters to assess the intensity of a set of pre-defined positive and negative flavour attributes in the oil. They score each of the attributes from 0 to 5 depending on their perception of the intensity of flavour as follows:
0: absence of perception
1: intensity slightly perceptible
2: intensity light
3: average intensity
4: great intensity
5: extreme intensity
TESTING THE POSITIVE ATTRIBUTES
Each of the tasting actions (Swirl, Sniff, Sip and Swallow) focuses our attention on a specific positive attribute in the oil. First, we evaluate the olive fruit aroma (fruitiness) by inhaling from the glass. When the oil is in our mouths we further evaluate the aroma retro-nasally as well as determine the amount of bitterness on our tongues. Finally, we determine the intensity of the oil’s peppery tones (pungency) in our throats as we swallow it.
This refers to the aroma of fresh, undamaged olive fruit in the oil, which is perceived through the nostrils when we Sniff the oil as well as retro-nasally while oil is in the mouth. You should try to define the fruity type, green or ripe, and recognise the presence of attributes such as grass, leaf, apple and other fruits.
Bitterness is a prominent taste in fresh olives and is one of the primary flavour components perceived through receptors (taste buds) at the back of the tongue.
This is a peppery sensation that you feel in your throat after you swallow some oil. Sometimes oils are referred to as one or two “coughers” as this is a common response to pungency.
TESTING THE NEGATIVE ATTRIBUTES
These are the negative flavours tested by the International Oil Council. Ideally, these should not be present in good quality Extra Virgin Olive Oils.
WINE-VINEGAR: Typical odour of wine or vinegar due to fermentation of olives.
ROUGH: A tactile sensation in the mouth due to the texture of oil.
METALIC: Oils processed or stored with extended contact to metal surfaces.
MUSTY: Mouldy smell from olives being stored too long before pressing.
MUDDY: Typical odour of oil that has been stored too long on its own sediment.
FUSTY: Due to olives fermenting in piles while in storage waiting to be pressed.
RANCID: Old oils that have started oxidizing due to exposure to light or air.
Tasters then rate the overall grading using a 9 point scale with 9 being the highest grade for oils with exceptional sensory characteristics and 1 for products with the worst qualities. An oil can be classed as Extra Virgin Olive Oil if it achieves an average score of 6.5 or higher from the panel of judges.
DESCRIBING THE PALATE
While the IOC assessment offers an objective method to determine if an oil has defective flavours or not, we think it is important to think about the flavour profile or palate of the oil which will help you with food pairings and cuisine type. This simple method outlined below allows you to describe the oils as mild, medium or robust;
These lighter oils tend to be buttery, mellow, delicate and soft; these pair excellently with light or delicate dishes such as fish, soups, vegetables, pesto, eggs and potatoes.
These oils are slightly more robust and generally have a grassier and more complex taste profile. These oils have a peppery finish and are great with steak, bruschetta, tomato sauces, pasta, and any dish where you want to cut through and brighten up the flavours already present.
These oils are made from olives that are picked when they are primarily green, tend to have a more assertive and peppery flavour, generally with notes of green tomato vines, green tomato leaf and green apple skins.
Full-flavoured, more robust dishes made with red meat and tomato-based sauces, as well as hearty stews, even steamed vegetables and salads, pair well with these fruitier, more flavorful oils.
BITTER: considered a positive attribute because it is indicative of fresh olive fruit
BUTTERY: creamy, smooth sensation on the palate
FRESH: good aroma, fruity, not oxidized
HARMONIOUS: balance among the oil’s characteristics with none overpowering the others
PEPPERY: stinging sensation in the throat, which can force a cough
ROUND/ROTUND: a balanced, mouth-filling sensation of harmonious flavours
SPICY: aroma/flavour of seasonings such as cinnamon, allspice