Yes, you need to wash fresh mushrooms. Here’s how
It’s an age-old question: Do mushrooms need to be washed?
The answer is pretty simple: Absolutely.
The confusion about how to clean mushrooms comes from the disproved belief that because mushrooms are 92% water, they will absorb excessive water when washed and become too soggy to properly cook. The truth is that there are other vegetables with an even higher water content, including spinach, tomatoes and cucumbers, and we have no qualms about giving them a bit of a bath before cooking and eating. Mushrooms are no exception — if you know how to wash them.
“Back in cooking school, we were taught that you wiped each individual mushroom with a damp paper towel,” says chef Sara Moulton, host of the PBS series “Sara’s Weeknight Meals,” “but imagine doing that with three pounds of mushrooms. It would take forever!”
It was while working at a restaurant in France in 1979 that Moulton learned that mushrooms didn’t need to be handled quite so delicately. “We would fill up a bowl with cold water, put in about six mushrooms, swish them around while counting to 10, then we got them the hell out of there.” Any compost or dirt clinging to the mushrooms fell to the bottom of the bowl, and the mushrooms weren’t submerged long enough to absorb a significant amount of liquid.
Like any produce that has been traveling in trucks and handled by multiple people, from farmers to other shoppers, it’s a good idea to give those fungi a fresh start before they land on your dinner plate.
Here’s how to handle different types of mushrooms.
Cultivated mushrooms
The dirt that you might see on white button, brown cremini and other cultivated mushrooms is typically a peat-based compost, while shiitakes and oyster mushrooms might be grown in a substrate composed of sawdust or straw.
Whether whole or pre-sliced when purchased, any of these mushrooms can be washed just before you are ready to cook using Moulton’s method, then spread out to dry on paper towels or a clean cotton dish towel. You can also place the washed mushrooms in a salad spinner lined with paper towels or a dish towel and give them a couple of quick spins to remove the excess water.
Portobello mushrooms
Portobellos — which, by the way, are just adult cremini mushrooms — can be washed by the same method as other cultivated mushrooms, but it’s a good idea to remove the gills on the underside of the cap first, as they can retain water. Moulton likes to use the serrated edge of a grapefruit spoon to simply scoop the gills out, then pats the cap dry with a kitchen towel after washing.
Foraged mushrooms
When it comes to foraged mushrooms, such as chanterelles, maitake, chicken of the woods, or porcini, there will be dirt, pine needles and even the occasional insect that may need to be removed. In this case, professional forager Alexis Nikole Nelson instructed in a Washington Post interview, “Dunk your finds while scrubbing in a bowl of water and vinegar, and then give them a rinse before eating or putting in the fridge.”
A solution of one part vinegar or lemon juice to four parts water will do the trick, and you can use a mushroom brush or even a soft toothbrush to scrub off any stubborn dirt, then rinse with fresh water. With a large clump of foraged oyster or maitake mushrooms, pull the clump into smaller pieces, which will make them easier to clean of debris.
As to morels, which can collect dirt and sand in their various nooks and crannies, give them a rinse under running water, then use a brush — even a pastry brush will work well — to tease out any grit.
And if your washed mushrooms happen to soak up a little excess water, don’t fret — Moulton has a solution for that, too. “All you need to do is cook them a little bit longer,” she says. “Any extra water will evaporate and they’ll be just as delicious.”