Found in 2 comments on Hacker News
It really matters HOW an oil is produced.

"Good" olive oil enjoys a really healthy process, as opposed to most "new" oils available commercially only in recent years.

However, there is a lot of "fake" or altered olive oil in circulation. Be well aware of this. [0] [1]

[0]: https://www.forbes.com/sites/ceciliarodriguez/2016/02/10/the...

[1]: https://www.amazon.com/Extra-Virginity-Sublime-Scandalous-Wo...

mywittyname · 2017-11-27 · Original thread
If you want high quality olive oil, your choices are either American or Spanish. Italian olive oil (at least, the exports) are garbage and probably 49% Not Olive Oil.

I bought Italian EVOO for the longest time (it's all most super markets carried), but never understood why so many people loved to eat it over pasta, or said you shouldn't fry with it. I always thought the flavor was kind of neutral and always pan-fried it without issue. Then I learned about the wide-spread fraud in the Italian EVOO market[0] and decided to pick up some expensive ($9 a cup) Californian EVOO.

The difference in flavor was so stark, like comparing a steak and an all-beef hot dog. Good EVOO has a wonderful, vibrant flavor. Now we eat pasta with just EVOO and cheese pretty often. I also discovered that when you stir fry with good EVOO, it will take on a bitter, burnt flavor.

[0]https://www.amazon.com/gp/product/0393070212/ref=as_li_ss_tl...