What should roasted pistachio oil smell like? I've had a bottle of roasted pistachio oil sitting in my refrigerator for about two years now, that someone gifted me.  Every day I open the refrigerator and it stares at me.  Today I decided that enough was enough, and I'd try and finally get it out of my life by substituting it in a biscotti recipe.

It's over a year past the expiration date, but I've been storing it in the fridge ever since I got it.  Now, I'm very familiar with what rancid neutral oils smell like, and even rancid olive oil.  But I'm not sure how to detect whether a roasted nut oil has gone rancid.  It has a very strong smell, but when I taste it, I don't notice any bitterness.

What should it smell like, if it is in fact still fresh?
You are the best judge here. and you have stated that it doesn't smell bad.  Go ahead and use it - it will be ok.  The fact that it is a 'roasted' nut oil is no different from it being an 'unroasted' one.