David Lebowitz, famed blogger of "Living the Sweet Life in Paris," wrote a fantastic how-to guide to choosing, using and treating your olive oil. I agree with 100% of it, so if you want to buy the right olive oil and make it last, consider these tips:
1. Keep olive oil out of the light.
I know you've spent a lot of money on your oil and you want to look at all those pretty labels lined up on your countertop. But too bad; it's one of the absolute worst things you can do to oil. Light destroys olive oil, and other specialty oils as well, so stow it away. Nothing destroys olive oil faster than light. Except heat.
2. Keep olive oil away from heat.
That means don't store your olive oil on that shelf above your stove, even though that's where it's handy. Keep it away from sunlight as well. It's best not to store olive oil in the refrigerator. If you do, when you take it out the condensation can dilute the oil and cause it to spoil quicker.
3. If you can, taste before you buy.
This speaks directly to my recent post, "Great Idea: Bottle Your Own Olive Oil." Oil changes from batch-to-batch, and many places offer you a chance to taste it before you buy. Take a good smell first; a lot can be determined by how the oil smells before you even taste it. Is it nutty, grassy, sweet, oily, or 'green'? All those are qualities you might like, or not. Look for markets in your area that offer tastings, and patronize the stores that do as thanks in return.
4. Have two olive oils on hand.
Just as David does, I keep one less-expensive olive oil for cooking—my 'house' oil right now is Olivier's House Blend— and I keep at least one other for salads and serving with uncooked dishes, which is always a premium, top-quality olive oil (ours is St. Helena Olive Oil Co.'s Buona Volunta or Italian import Monini). I personally don't recommend cooking with an expensive oil since the finer flavors get lost in the madness. A less-pricey, but good-quality oil is fine to use for sauteing onions and vegetables. And even marinating feta.
5. Don't pay much attention to the country of origin.
Just like people say, "American food is bad", there's good American food and there's bad American food. Same with olive oil. There's good Tuscan olive oil and there's bad Tuscan olive oil. Just because something says 'Tuscany' or 'Provence' on it doesn't mean it's necessarily good or bad. And "Made In France" means something different than "Product of France". "Made In..." means the oil is actually made in that country with olives that are supposed to be grown and pressed there. "Product of France" means the olive oil was bottled there, but could be made from olives from North African that were shipped to Hungary then transported to France for bottling. It's not that that's necessarily bad, but some countries have different pesticide and labeling standards and it's nice to be up-front about those kind of things with consumers so we know what they're getting.
6. Spend more, get more.
Sure you can buy toothpaste from China for 99 cents vs Crest for $3. But some of the Chinese stuff has anti-freeze in it and the Crest (presumably) doesn't. Price does not necessarily equal quality and it's okay to be frugal so you don't need to break the bank. There's many olive oils that cost less than $10 per bottle that will last you months, although I'm happy to spend a bit more. It's your temple—feed it well.
7. Use olive oil while it's still in its prime.
Good extra-virgin olive oil will last about a year if stored properly. Cheap olive oils are often already rancid when you open them since they're mechanically-harvested, which bruises the fruits. Then they're allowed to sit for a few days before pressing, which increases the chance and speed of spoilage. I always taste a bottle of oil when I open it before using.
8. Organize your own tasting!
In spite of what I, or anyone else says, only you know what you like and what price you feel comfortable paying for a bottle. While some folks find paying more than $10 for a bottle of olive oil outrageous, they think nothing of spending many times that on a bottle of wine, which normally doesn't last as long. Check your local markets and taste what available. Buy various oils and taste them with friends. Read up and learn what makes a good olive oil worth it, and you'll get much more appreciation every time you drizzle some of that fragrant, smooth oil from the bottle.
So next time you're in the market for olive oil, remember this guide. It'll help you discover some wonderful go-to olive oils that you can call your own.