Yeah I asked one of my friends from Italy how best to tell and the first thing she pointed to was the price. The other one is that there is a seal that Italy has started to put on the 100% bottles that help certify it. Clear bottles are also a huge flag it needs to be in green ones and to check your olive oil you can put it in the fridge and regular olive oil will solidify while cut stuff will not! 

Cje95

Apparently MOST of the supposedly 100% olive oil out there is actually diluted with vegetable oils. It's apparently quite difficult to detect this. 

Signal312

econ

What is the price of olive oil in the country?, in Brazil the price is exploding

Hannah

So I read about this a few months ago but with the Greece wild fires from last year and the increase in demand, there is a huge supply gap! Some brands are shifting to cutting their olive oil with other seed oils to not send the price through the roof but there is a huge huge supply and demand issue! 