Bagged salads: the yuck factor.(up front: News / Trends / Advice)

We've heard the complaints, and have even made them ourselves: You buy a bag of prewashed lettuce, paying a premium because it's convenient and attractive, open it on or before its use-by date, and find brown or gooey leaves among the green. Is it your imagination, or is this stuff old before its time? What's more, the bag might say "ready to eat," but are unwashed greens safe?

With $2.5 billion of precut salads sold in supermarkets in one year, the concerns can become serious for a lot of consumers. In late July, there was a voluntary recall of some packages of Classic Salads lettuce and spinach that could have been contaminated with salmonella. (The potential problem was found during routine sampling by the company, and no illnesses had been reported as of press time.) And in 2005, about 250,000 packages of Dole salad were voluntarily recalled because of possible contamination with E. coli bacteria. Without admitting fault, Dole recently settled four lawsuits and an undisclosed number of claims from consumers who complained of stomach cramps, bloody diarrhea, or, in one case, acute kidney failure after eating the salads.

How we tested. We chose six bagged salad blends from two of the biggest purveyors: Dole's American, Classic Iceberg, and Spring Mix; and Fresh Express's Double Carrots, Green & Crisp, and Spring Mix.Then we performed two types of tests. For our yuck test, we bought 32 bags of those salads, opened them on or before their use-by date, sniffed, and went through them leaf by leaf, weighing the pieces deemed inedible or undesirable. For our bacterial test, we sent 62 bags to a lab to have them analyzed for generic E. coli, which can indicate contact with fecal material but isn't necessarily hazardous to your ...