Why buy pricey spices?

Next time you're replenishing the spice rack, check the difference in cost from brand to brand. We've paid 35 cents per ounce for Costco's pure vanilla extract compared with $3.34 for McCormick's, for example (quite a spread even given that the Costco was giant-sized). And when it comes to oregano, you could pay $1.10 per ounce for Walmart's Great Value or more than $7 per ounce for Spice Islands.

How we tested. Our trained tasters tried oreganos and cinnamons at three price levels. They tasted oregano steeped in hot water to make a "tea," in a simple tomato sauce, and on bread with melted cheese. They tasted cinnamon stirred into unsweetened applesauce, baked in sugar cookies, and on toast. The results could lead to smarter choices when you buy.

When we asked manufacturers about price differences, they cited several reasons:

• Different growing regions. Most oregano is cultivated in Turkey and the Mediterranean, for instance; the pricey Spice Islands product is grown in the wild in Mexico. (Mexican oregano is a different species, and it's "more intense and has a stronger impact," says Carol Kitchen, research manager of ACH Foods, owner of the company that sells Spice Islands.)
• Percentage of volatile or essential oils. A higher content is key, says Daniela Massey, product development manager for The Spice Hunter. "Essential oils are what give plants their aroma and flavor," she says.
• Quality control. "Even in the U.S., products aren't ready to go from the field to your mouth," says Al Goetze, vice president of spice procurement for McCormick. He cites "strict quality control from the fields to grocery store shelves" to minimize exposure to allergens, metals, and bacteria.
• Packaging. Glass containers are more expensive than plastic, which are pricier than the plastic bags that hold the cheapest spices.

What we found. When the cinnamon was baked in cookies, tasters found no differences. When tasted in other recipes, the most expensive oregano and cinnamon had a slightly more intense flavor than the rest. A pricey spice could be worth trying in a simple dish (oregano on fresh tomatoes, for instance) or where it's the main ingredient (as with cinnamon buns). For recipes with many ingredients, you probably don't need to pay a premium.

When you buy, check for expiration dates. Spices lose strength over time; many should be replaced after two or three years. If dates are absent, write the purchase date on the jar. Store spices in a dark, dry, cool area.