Should You Be Washing Pre-Washed Lettuce?
A good rule of thumb to keep is, before cooking, eating, handling, or putting anything near your mouth, make sure that it's clean. Ingredients are no good if they are covered in muck. Your first step should always be to clean them thoroughly.
But what about ingredients that come with the pre-washed label? As is the case with many products and their labels, the pre-washed title does mean what it says. Pre-washed vegetables, including lettuce, are safe to consume without additional cleaning. According to Eating Well, the produce industry standards for cleaning vegetables are very stringent. The vegetables are cleaned several times from farm to grocery store for everything from dirt and bugs to bacteria, parasites, and other microbes. Per NPR, there are many opinions floating around as to whether or not pre-washed produce should be rewashed at home. Still, the majority of food safety experts hold that there is no need and actually a small bit of risk to cleaning your own vegetables.
How clean is your kitchen really?
There are two main reasons why washing your pre-washed lettuce may not be the best move. First, and perhaps most obvious, is that the cleaning process that you go through in your kitchen is unlikely to be as stringent as the cleaning process that the lettuce has already gone through. If the bacteria and germs survived the professional treatment, it is unlikely that running the lettuce under cold water for 10 seconds will make any difference.
The second reason is that cleaning yourself can spread bacteria from your kitchen onto your lettuce. Again it is unlikely that your kitchen is as stringently clean as the produce treatment plants or processes, so exposing lettuce to your not-so-clean kitchen may be what actually gets your lettuce nasty in the first place. As Master Oogway says in "Kung-Fu Panda" (and Jean de la Fontaine, too), "A person often meets their destiny on the road they take to avoid it." And as NPR says, if you really want to make sure your lettuce is clean, just stir-fry it. No bacteria are surviving that heat.