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Mushrooms 101: Everything You Need to Know

By the editors of Cook's Illustrated

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Learn the test kitchen's best tips on buying, storing, and cleaning mushrooms.

Long gone are the days when the only mushrooms in the produce aisle were white button, portobello, or cremini. Some stores now display up to a dozen different kinds, and many that were once available only seasonally are now farmed almost year-round.

But whether cultivated or wild, common or rare, mushrooms are easy to prepare and add intense flavor to everything from soups, stews, and sauces to meats, stuffings, and egg dishes.

Here are our recommendations for how to shop for, store, and clean this umami-packed ingredient.


What Should You Look for? We recommend buying loose rather than prepackaged mushrooms so you can inspect their condition and quality. Look for mushrooms with whole, intact caps and avoid those with discoloration or dry, shriveled patches. The mushrooms should feel faintly damp but never moist nor slimy, and their texture should be springy and light rather than spongy.

Aroma is another important indicator of quality and intensity—the stronger the sweet, earthy scent, the more potent and flavorful the mushrooms. Don’t buy mushrooms if they smell sour or fishy, and be sure to pick ones with large caps and minimal stems since the latter are often discarded.


The Dos and Don’ts of Keeping Mushrooms Fresh: Due to their high moisture content, mushrooms are very perishable. They can go from plump to shriveled and slimy in no time. Over the years we’ve tested numerous storage methods; here’s what we’ve decided works best.

DON’T wrap mushrooms in a paper bag, as many other sources suggest. It turns the fungi spongy and wrinkly.

DON’T cover mushrooms with a damp paper towel (another common technique), as it only speeds up their deterioration.

DO store loose mushrooms in a partially open zipper-lock bag, which maximizes air circulation without drying out the mushrooms. Leaving the bag slightly open allows for the release of the ethylene gas emitted from the mushrooms.

DO store packaged mushrooms in their original containers. These containers are designed to “breathe,’’ maximizing the life of the mushrooms by balancing the retention of moisture and release of ethylene gas. If you open a sealed package of mushrooms but don’t use all the contents, simply rewrap the remaining mushrooms in the box with plastic wrap.


Should You Wash Mushrooms You’re Going to Cook? If they’re whole, yes. Although many sources advise against washing mushrooms (to avoid their soaking up any additional moisture) and suggest brushing them instead, once we learned that mushrooms are over 80 percent water we began to question their ability to absorb more liquid. To find out, we rinsed a batch in cold water, weighing them before and after their wash. We found that six ounces of mushrooms gained only about a quarter ounce of water, and most of this was beaded on the surface.

Cut mushrooms are a different story. The exposed flesh will absorb water like a sponge, so rinse mushrooms before slicing them. And be careful not to wash mushrooms until you are ready to cook them or they will turn slimy.

We like to use a salad spinner to wash whole mushrooms:

1. Place mushrooms in a salad spinner basket and spray with water until dirt is removed.

2. Put the basket into the salad spinner and spin the mushrooms dry. Use a paper towel to blot up any remaining moisture.

Should You Wash Mushrooms You’re Serving Raw? In a word, no, because rinsing mushrooms can cause discoloration, and you want your meal to look as good as it tastes. We recommend cleaning mushrooms that will be served raw by brushing them with a dry toothbrush.

RECIPE FOR MEMBERS: Quick Mushroom Ragu

Making a true, long-simmered ragu means tending the pot for hours. We found a way to achieve deep, satisfying flavor in just 30 minutes. Portobello mushrooms gave our dish bulk, while smoky porcini gave it concentrated flavor. Adding tomato paste and fresh crushed tomatoes to our mushrooms after they’d browned sweetened our sauce but also let the mushrooms shine through.

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