How to store fresh mushrooms

That is the whole rule, and it is close to the opposite of what most people do, which is leave them sealed in plastic on a shelf.

Do this:

• Store them in a paper bag in the refrigerator. Paper lets moisture escape, so a folded-over brown paper bag or a loosely covered container both work.
• Keep them in the main body of the fridge, not the crisper drawer. The crisper is built to hold humidity in, and humidity is the one thing mushrooms do not want.
• Keep them dry. Do not wash mushrooms until right before you cook them. Water sitting on the surface speeds up spoilage.
• If they came home in plastic, get them out of it and into paper as soon as you can.

Avoid this:

• Sealed plastic bags and airtight containers. They trap moisture, and trapped moisture is what turns mushrooms slimy.
• Sitting in their own condensation. If the container fogs up, it is too wet in there.
• Room temperature. Warm mushrooms break down fast. Cold slows everything down.

Fresh mushrooms are best within several days of getting them home, and sooner is always better than later. As a general guide, a dense mushroom like Lion's Mane holds a little longer than the thin, delicate oysters, but both reward you for cooking them while they are fresh. Those are general ranges rather than a promise about your particular batch.

The clock starts when a mushroom is harvested, not when it reaches you. Buying from a farm that sells the same week it picks already puts you days ahead of anything that spent that time in a distribution truck.

The mushrooms we sell fresh are primary decomposers. They grow on wood rather than in soil or compost, the way a button mushroom does, so they come off the farm clean and there is nothing to scrub off. Trim away any bit of substrate still stuck to the base and cook them as they are.

If you do rinse them, rinse fast and pat dry. Mushrooms behave like sponges, and a soaked mushroom steams in the pan instead of browning.

Trust your eyes, your nose, and your fingers. A mushroom that is past it will tell you.

Still good to cook:

• Slightly drier, or a little browned at the edges. Fresh mushrooms are still alive and still losing water, so browning as they dry is normal and rarely changes the flavor or the texture.
• Minor spotting or discoloration.
• Firm, or only a touch softer than the day you brought them home.
• A white, satin-like fuzz creeping outward from the mushroom. That is mycelium looking for more food or moisture, not spoilage.

Time to compost:

• Slimy or sticky to the touch. That is the clearest sign there is.
• A sour, fishy, or off smell. Fresh mushrooms smell earthy and clean.
• Green or otherwise odd-colored growth, heavy dark discoloration, mushiness, or visible mold.

There is no waste guilt here. Mushrooms are compost gold, and a batch that got away from you goes right back into feeding soil. Cook the good ones, compost the rest, and store the next batch a little drier.

Dried is not the same as ruined. If a batch goes dry in the fridge with no mold and no off smell, it is perfect for soup. Dried mushrooms rehydrate into stocks, stews, and sauces with a deeper, more concentrated flavor than they had fresh.

Anyone who knows they will not get through a full amount in a week can dry the extra on purpose instead. Keep it in a sealed jar somewhere cool and dark and it is there whenever you want it.