This posting invites your response. How do you use olive oil? What do you look for?
The first resource I go to for learning about olive oil is Deborah Krasner. Her book, The Flavors of Olive Oil: A Tasting Guide and Cookbook, won a 2003 James Beard Award. In her book she ponders the question of choice and suggests there are clues from packaging to be made when choosing olive oil. (Simon & Schuster, NY. 2002. ISBN: 0-7432-1403-X)
A summary guide from Krasner for use at store shelves or shopping online:
1. Look for pride of production and signs of humans, not just machines. Check for foil-wrapped bottles, cardboard or wooden boxes, or handwriting on the label. Be cautious about marketing strategies and gimmicks.
2. If you have a choice, ceramic makes the best container. Metal is better than glass because light deteriorates the oil's qualities. Dark glass is better than clear.Note stamped production number, upper left, and year of production, center bottom.3. Look for a screw cap that covers a plastic pouring spout. Cork stoppers can deteriorate with time and poor handling. Oxygen leaking into the oil through old and cracked or misshapen cork compromises the desirable qualities of the oil.
4. Look for harvest or bottling dates. Dates stamped on labels are another sign you can have confidence in the contents.
5. Olive oil should last at least one year if kept away from heat, light, and oxygen. If a clear glass bottle is the only choice, store it wrapped in aluminum foil.Examples of packaging and storage.
I probably wouldn't have paid much attention to olive oil if I hadn't known Deborah Krasner already. She and I cook together regularly with friends Tukta Long and Sharon Myers and use olive oil often.