Sometimes oil tickles the throat: what does that mean?

This sensation into the throat doesn’t depend on acidity, that is imperceptible by taste, but it depends on the natural components that distinguish the fragrance and flavour of oil. Those components are essential for performing an antioxidant action for oil, and preserving it from going rancid. 
This smart is usually more perceptible if oil has been produced quite recently: when few months have passed, the oil flavour becomes sweeter and finally the smart disappears.
Oil is a natural product obtained from olives that are influenced by many factors, both environmental and climatic; such factors are for example quality, age and position of olive trees, rainfalls, etc…: so it is normal to perceive that sometimes oil tickles the throat.