There are three characteristics that you are looking for when you taste olive oil.
Fruitiness, Bitterness & Pungency
These three characteristics should all be in balance, no matter how strong or subtle they may be. You should not get one or two of these standing out and overpowering the others.
The olive oil can be strong and robust, where all three of these are present and they really assert themselves on your palate. It can be soft and mild, with these three offering a pleasant delicate balance, and oils can fall anywhere between these two ends of the spectrum. The important thing is that the three flavours are balanced.
You will pick this up on the front of your tongue.
The olive is a fruit and so you should notice fruit flavours. These will be influenced by how ripe the fruit was when picked. Just like other fruits, olives will become sweeter as they ripen, and this sweetness, or its absence, will come through into the oil.
It is often possible to pick up other flavours that remind you of different fruits. Commonly these other flavours might include green or ripe tomato, banana, and fresh cut grass.
Ripe fruit yields oils that are milder, aromatic, buttery, and floral. Green fruit yields oils that are grassy, herbaceous, bitter, and pungent. Fruitiness also varies by the variety of olive.
You will experience this on the middle of the tongue.
If you ever really want to taste “bitter” just try biting into a fresh olive straight off the tree, and you will instantly know all about this flavour. Some olive growers do taste fruit like this so that they can develop an ability to predict how the final oil may taste.
In tasting olive oil we are looking for a mostly pleasant acrid flavour sensation on the tongue.
This is the flavour that will hit the back of your mouth and throat.
It is a pepperiness that will often come through after the other flavours. Olive tasters often talk of a “one or two cough” oil depending on how much bite it had on the back of the throat.
In a good oil this should be a pleasant sensation that gives “life” to the oil
Remember that no matter how mild or robust the oil may be, we are looking for a balance between these three flavours.