Erol Karakaplan, who has been working as a pure olive oil taster for more than 40 years, says:
Olive oil must pass the exam of the nose, eye, and throat in order. Smell it first. Smell the oil that you drip into the hollow of the thumb, by closing one hole of your nose. It must smell fresh grass.
Then look the olive oil with your eyes. Put the olive oil in a narrow glass and gently shake it around its axis. It is pure if the olive oil fluctuates and goes down slowly from the edge of the glass.
it should be heavy when looking at the oil, but not when you taste it. Take a sip of olive oil from the glass and turn it in your mouth with your throat closed. Let it sit, there will be no weight in the mouth, its density will be fine, wait a little.
It's time for the throat pulling. This time the throat will talk about olive oil. Good oil does not bitter the throat.
There is an old adage in Turkey. 'pleasures and colors are indisputable'. If it passed these exams for you, it is good olive oil.