What's the 'extra virgin' in Extra Virgin Olive Oil?

What does ‘extra virgin’ mean?

I work part time at a supermarket, and a customer came up and asked me this today. I had no idea.

Extra virgin olive oil is cold pressed and unrefined. Lighter olive oils have been refined to reduce acidity, and are consequently lighter in color and flavor.

Virgin means the oil’s made from the first cold pressing. Extra virgin means it has an acidity of no more than 1%. It has a sweeter flavor than the other grades and is used more for marinades and dressing than for cooking and sauteeing.

Now ask about balsamic vinegar…
JuanitaTech, somewhat of a gourmet…

OK, I’ll bite JT. What’s the dope on balsamic vinegar?

Incidentally I do have an interest in this since I always marinate my cooked vegetables in balsamic vinegrette and have recently begun making my own from b. vinegar.
I guess it’d be nice to know what I’m working with here.

Thank you, you two.