Is it really OK to wash your mushrooms before cooking?
Tomorrow marks the first day of fall, and there’s one ingredient I associate with fall almost as much as I do apples — mushrooms. Whether I saute creminis with butter and shallots and serve them as an easy side, or fry a wild mix with thyme and toss with pasta, this earthy vegetable tastes, at least to me, like fall leaves, crisp air and changing seasons.
But as much as I love eating mushrooms, I hate prepping them. The conventional wisdom — don’t ever let your mushrooms even see a bowl of water for fear of sogging out — makes it even more annoying to clean them. Mushroom brushes work, kinda. Damp towels work, kinda. Inevitably, though, I spend way too much time fiddling with my ’shrooms and not enough time actually enjoying them. So do I really need to go through all of that trouble?
In most cases, no.
Much like the theories that even a smidge of soap will ruin cast iron or that steaks will spew juices when poked with a fork, the rule that mushrooms should never be washed simply doesn’t hold up to testing. Two reputable sources, Cooks Illustrated magazine and J. Kenji Lopez-Alt, formerly of the website Serious Eats, ran tests where they washed plain ol’ button mushrooms in water, spun them dry and measured the amount of water absorbed. The result? Lopez-Alt measured an absorption of around 2 percent of the mushrooms’ total weight in water, which is certainly something, but not enough to really affect cooking.
That said, these tests were done using whole mushrooms; if you prefer to purchase pre-sliced mushrooms, you will not want to dunk them in water and spin them dry. They will, inevitably, fall apart. (But you should really be buying whole mushrooms — they’re fresher and not that hard to slice!)
Another point worth mentioning: Any time you purchase cultivated mushrooms, such as cremini, portobello or white button, and you see what looks like dirt in the package, you’re not actually looking at dirt. These ’shrooms are grown in sanitized, composted peat moss, which is totally safe to eat. (Whether you want to or not is your own personal choice.)
Wild mushrooms, such as chanterelles and oysters, may require a bit more work. These can come with all kinds of dirt, leaves and needles attached. They are, after all, harvested from forest floors, so will show up in your home all different levels of dirty. They are also often more delicate than the mushrooms mentioned above, so will likely fall apart when spun. You can still rinse whole wild mushrooms, but you’ll want to take care when drying them.
So the next time someone gasps as you dunk a strainer full of mushrooms into the sink, tell them to relax. You’ve got science on your side.