Ideally, find a store where you can taste olive oils in a range of styles before you buy them, and where the staff can answer a few basic questions.
When choosing bottled oil, prefer dark glass or stainless steel containers that protect against light, buy a quantity that you’ll use up quickly, and keep it well sealed in a cool, dark place. Even an excellent oil can rapidly go rancid when exposed to heat, air or light.
Color has little to do with quality. Good oils come in shades of vivid green to gold to pale straw.
Seek out freshness and choose oils that smell and taste vibrant and lively and don’t be put off by bitterness and pungency.
Pungency is a sign of freshness and coincides with the amount of polyphenols (antioxidants).
More bitterness and pepper= greater health benefits (antioxidants, anti-inflammatories and other healthy minor components of top quality oil).
If you can’t taste an olive oil, make sure the label says “Extra Virgin” since other categories- “pure”, “light “, “pomace” undergo chemical refining which strips the oil of flavor and many of the health benefits.