I used to soak my mushrooms like they were dirty socks.
Turns out, that’s basically the worst thing you can do—and I mean that literally, not in the dramatic way people throw around ‘literally’ these days. Mushrooms are like tiny sponges, except they’re not trying to be helpful about it. They’re roughly 80-90% water already, give or take, and when you run them under the tap or dunk them in a bowl, they absorb even more moisture faster than you’d think possible for something that looks so innocent. The cell structure is porous, almost architectural in how it’s designed to pull in liquid, which makes sense if you think about how fungi actually grow in damp environments. But here’s the thing: once a mushroom gets waterlogged, it loses that firm, meaty texture that makes it worth cooking in the first place. It gets slimy. The flavor dilutes. You end up steaming them in their own absorbed water when you hit the pan, and nobody wants that sad, grey pile of mush. I’ve seen professional chefs get weirdly passionate about this topic, and honestly, I get it now.
The brush method isn’t new—it’s been around in French kitchens for decades, maybe longer—but it feels almost rebellious when you first try it. You take a soft-bristled brush, something like a mushroom brush or even a clean paintbrush if you’re improvised, and you just gently sweep away the dirt and debris. That’s it. No water involved.
Wait—maybe I should back up a second, because the science here is actually kind of fascinating in a nerdy way that I didn’t expect to care about.
Why Water Turns Your Fungi Into Disappointing Wet Rags (And What’s Actually Happening at the Cellular Level)
Mushroom cells have these thin walls made mostly of chitin—the same stuff that makes up insect exoskeletons, which is wild if you think about it—and those walls are permeable. When water molecules encounter that porous surface, osmosis kicks in, and the mushroom essentially can’t help itself. It pulls moisture inward to try to balance concentrations, except there’s no real balancing happening because you’re dunking it in way more water than it needs. The absorption happens in minutes, sometimes seconds depending on the variety. Portobellos are particularly bad offenders because they’re mature and have more exposed surface area under the cap. Shiitakes are slightly better but still vulnerable. Button mushrooms, the ones most people buy, fall somewhere in the middle—they’ll absorb water, just maybe not quite as catastrophically fast as their bigger cousins.
I guess it makes sense when you realize that mushrooms aren’t really plants anyway; they’re fungi, which operate under totally different biological rules. They don’t have the waxy cuticles or protective outer layers that vegetables develop. They’re soft. Exposed. Kind of defenseless against your well-meaning but misguided cleaning attempts.
The dirt on mushrooms is usually just substrate—the material they were grown in, like composted manure or sawdust—and it’s not harmful. It’s not like you’re dealing with pesticides or chemical residues the way you might be with, say, apples or lettuce. Most commercial mushrooms are grown in controlled environments anyway, so the ‘dirt’ is more aesthetic than dangerous.
The Actual Technique That Doesn’t Require You to Be a Culinary School Graduate or Own Fancy Equipment
Get a brush with soft bristles—natural fiber works great, but synthetic is fine too as long as it’s not too stiff. Hold the mushroom gently in one hand. Brush away visible dirt with short, light strokes. If there’s a really stubborn bit stuck in the gills under the cap, you can use the corner of a damp paper towel to spot-clean, but keep it minimal. Some people trim the very end of the stem where it was cut during harvest, which I do mostly out of habit now, but it’s not strictly necessary unless it looks dried out or damaged.
The whole process takes maybe 20 seconds per mushroom, which is actually faster than washing and then waiting for them to dry—because yes, if you do wash them, you’re supposed to let them dry completely before cooking, and good luck with that when they’ve already absorbed half their weight in water. I used to pat them dry with towels and convince myself it was working, but I was basically just redistributing dampness.
Honestly, the first time I cooked brushed mushrooms instead of washed ones, the difference was so obvious I felt a little annoyed at all the years I’d been doing it wrong. They browned properly. They developed that deep, caramelized flavor instead of just sort of sadly sweating in the pan. The texture stayed firm and almost steak-like, especially with thicker varieties.
There’s this quote I remember from a mycologist interview I read once—or maybe it was a chef, I forget—but they said something like, ‘Mushrooms want to be treated with respect, not drowned.’ Which sounds a little precious, maybe, but after you’ve tasted the difference, it doesn’t feel that dramatic anymore. It just feels true.
Some people worry about bacteria or contamination, which is fair, but cooking mushrooms properly—meaning high heat, enough time for them to reach safe internal temperatures—kills off anything that might’ve been lurking anyway. The USDA doesn’t reccomend any special washing procedures for mushrooms beyond removing visible dirt, and they’re pretty cautious about food safety in general. If you’re immunocompromised or dealing with specific health concerns, obviously consult appropriate guidelines, but for most people, brushing is perfectly adequate and actually better for the final dish.
Anyway, I’m not saying this will change your life or anything. But it might change your mushrooms, and if you cook them even semi-regularly, that’s not nothing.
