Extra Virgin Olive Oil : What Factors Determine The Taste
High quality extra virgin olive oil is like fine wine, there is an incredibly wide choice and taste. Each olive oil has its own unique taste characteristics depending on the type of olive or varietal the olive oil comes from, the soil conditions where the olive trees are grown, when the olives are harvested, how the olives are treated during the harvesting and pressing to produce the olive oil and a whole host of other factors.
For example, oil made from predominantly unripe (green) olives contain flavours described as grassy, artichoke, or tomato leaf, whereas riper olives tend to yield softer flavours often described as buttery, floral, or tropical.
The above descriptions are associated with high quality, extra virgin olive, but trained tasters also learn to identify negative characteristics. Flavour defects in olive oil are associated with problems with the olive fruit (olive fly, frozen conditions), improper handling of olives during harvest (dirt, wet fruit, prolonged storage prior to milling), certain milling conditions (unsanitary equipment, excessive heat), and improper or prolonged storage after milling (oxidation).
An olive oil that is determined to have flavour defects is not of genuine extra virgin quality. According to the International Olive Council extra virgin olive oil must meet both chemical and organoleptic (flavour) standards that include the absence of flavour defects.
The first step in learning how to taste olive oil is to understand how our senses work. Perception of flavour relies on both our senses of taste and smell. The ability to taste is quite limited; receptors on our tongue can only discern sweet, salt, sour, bitter, and umami (the flavour of protein). All other information that we think of as flavour is actually perceived by smelling food through the back of our nostrils (retro-nasally) while it is in our mouths. To illustrate this fact, think about how little flavour we perceive when we have a cold (or indeed now Covid!). This is because one cannot smell food retro-nasally when one’s nose is stuffed up.
Tasting Olive Oil
When tasting extra virgin olive oil, much of the olive oil’s characteristics are perceived through the sense of smell. Though most people enjoy olive oil with other foods, the following steps allow us to focus on the olive oil’s flavour without distraction:
- Pour a small amount of olive oil (about 1 tablespoon) into a small tapered (wine) glass.
- Hold the glass in one hand and use your other hand to cover the glass while swirling the olive oil to release its aroma.
- Uncover the glass and inhale deeply from the top of the glass. Think about whether the aroma is mild or strong. You may want to write down descriptions of the aromas that you detect at this point.
- Next you slurp the olive oil. This is done by sipping a small amount of olive oil into your mouth while “sipping” some air as well. (When done correctly, you will make that impolite noise that would cause you to be scolded when you were a child!) Slurping emulsifies the olive oil with air that helps to spread it throughout your mouth, giving you the chance to savour every nuance of flavour with just a small sip of oil.
- Finish by swallowing the olive oil and noticing if it leaves a stinging sensation in your throat.
Each of the above actions focuses our attention on a specific positive attribute in the olive oil. Firstly, we evaluate the olive fruit aroma (fruitiness) by inhaling from the glass. When the olive oil is in our mouth, we further evaluate the aroma retro-nasally as well as determine amount of bitterness on our tongues. Lastly, we determine the intensity of the olive oil’s pungency in our throats as we swallow it.
Does The Colour Matter?
The olive oil colour is not addressed during sensory assessment. The reason is that contrary to the common belief that golden olive oil is mild and dark green olive oil is robust, colour is NOT an indicator of either the olive oil’s flavour or quality. In fact, in scientific assessments, we sample from specially designed blue glasses that obscure the colour of the olive oil. Tasting from a dark glass prevents us from having preconceptions about the flavour of the olive oil before we actually smell or taste it.
Practice Tasting Olive Oil
Once you are comfortable with the above tasting method, try the following exercise. Select three olive oils labelled as extra virgin olive oil, including an inexpensive imported brand from the supermarket. In between samples, clean your palate by eating a small piece of tart, green apple and then rinsing your mouth with water.
Consider the following as you evaluate each olive oil sample:
- Is the aroma of the olive oil pleasant or unpleasant?
- Is the olive oil aroma mild, strong, or somewhere in the middle (we’ll call that medium)? When assessing the second and third olive oils, note if the aroma’s intensity is weaker or stronger than the previous sample.
- Note 3 words (or phrases) that describe the aroma.
- Is the olive oil bitter, which is primarily sensed towards the back of the tongue? Would you describe the bitterness of the olive oil as mild, medium or strong? Is the intensity of the olive oil’s bitterness in balance with the intensity of the aroma?
- When you swallow the olive oil, how does it feel in your throat? Did the oil leave a mild impression, or did it sting your throat or make you cough? Is the intensity of the oil’s pungency in balance with the olive oil’s aroma and bitterness?
When you have completed the above exercise, take a few moments to review your notes. What were the characteristics that you enjoyed the most? Were there any characteristics of the olive oil that you didn’t enjoy? How did the supermarket brand compare to the other olive oils? Even without an experienced taster sharing their thoughts about the olive oils with you, there is much you can learn by tasting olive oils on your own.
Using this same tasting method, you can sample another set of oils on another day, and still be able to compare your responses to the first set; this is how we build our personal olive oil “vocabulary”. You will begin to recognize flavours and may even discover which varietals produce the flavours you prefer.
You will learn to compare the level of intensity for fruity aroma, bitterness and pungency, and will begin to identify olive oils as mild, medium and robust (intense). It’s a good idea to organize your tasting notes in a binder so you can review your past tasting experiences with new ones.
Taste is personal, so not everyone will agree on which varietals, and other factors, produce the best olive oil. However, tasting oils in a methodical fashion will help to educate your palate, and you will be able to select oils with flavour characteristics that you enjoy and enhance your meals.