The Food Lab: Better Home Cooking Through Science

“Mushrooms are basically living sponges. Don’t get
’em wet, or they’ll get soggy and you’ll never cook
them right.” Those same people will recommend that
you clean mushrooms by brushing them with a
special mushroom brush (oh, please), or maybe with
a damp paper towel. No wonder people don’t like
mushrooms—they’re a pain in the butt to clean!
But is this level of fear really necessary? I tested
out this theory by cooking a few batches of
mushrooms side by side. One I cleaned meticulously
with a damp paper towel. Another I cleaned under
the tap and shook dry in a strainer. The last I
cleaned under the tap and spun-dry in a salad
spinner. I weighed all the batches before cooking and
found that—hey, what do you know?—the washed-
then-drained mushrooms gained only about 2
percent of their weight in water, while the washed-
then-spun mushrooms gained about 1 percent. That’s
about 1½ teaspoons of water per pound, which in
turn translates to an extra 15 to 30 seconds of
cooking time.
What does this mean? It means that most of the
water you add by washing mushrooms clings only to
the surface. So long as you dry your mushrooms
carefully before cooking, you can rinse them as
much as you’d like. Cooking the spin-dried
mushrooms side by side with the paper-toweled
mushrooms confirmed this: they both cooked at
exactly the same rate.