You’ve probably heard that you should never, ever wash fresh mushrooms under running water. The thinking goes that they will soak up the water, making them soft and slimy in the final dish. But is that really true?
After tests of using a damp cloth to brush off the mushrooms and a quick rinse in a colander under running water, there is no difference in the texture of the finished dish.
One rule of thumb – Wash mushrooms right before cooking; if you let rinsed mushrooms sit around for longer than 10 or 15 minutes, the texture will indeed begin to suffer.