The fresh produce section of a grocery store promises what few other aisles can—whole foods, largely unprocessed, full of nutritional benefits like fiber, vitamins, and antioxidants. Part of that “pure food” message is spread by tiny nozzles mounted above leafy greens that spray water all over vegetables in timed intervals.
There are, of course, perceived benefits to doing this. Psychologically, shoppers probably like seeing produce that’s shiny with water, presuming it’s going to remain fresh. Some stores even pipe in thunderstorm sound effects to complete the visual.
The dirty truth? Watering them isn’t actually necessary in many cases. Grocery stores are doing it for another reason.
You might think that vegetables that have been uprooted and can no longer draw moisture from soil need a little topping off. In fact, the opposite is sometimes true: Excess water can lead to microorganisms thriving and spoiling plant tissue faster than if it was kept dry. If your kale looks a little brown in your cart, it might be because the store was too overzealous in watering it.
Stores have another reason for the showers. When fresh fruits and vegetables are doused in water, they absorb moisture. Since produce is often sold by weight, that means a saturated head of lettuce costs more than one that hasn’t been watered. When you get rung up, you’re essentially paying a premium for that water—by some estimates, up to 25 percent more.