The pros at Cook’s Illustrated says there’s science behind this method, which has recently blown up on TikTok. The reason why greens wilt is because they lose water, so bringing them back to life is literally a matter of soaking them in an ice bath, because the water enters through cell openings called the stomata. But instead of ten to 15 minutes, the site recommends the leaves be soaked for about 30 minutes. The Los Angeles Times says the ice bath also works with tired herbs in need of a little pick-me-up. As an added bonus, the ice bath helps get your leaves a bit cleaner, since the soak should also help loosen up whatever dirt might get stuck in green crevices.
There is one additional suggestion that Cook’s Illustrated tried out (so you don’t have to), and that’s to add two tablespoons of vinegar to the ice water, which is supposed to help the lettuce take in more water. The verdict? Hold the vinegar, but keep the ice bath, because there’s no reason to mess with a great thing.