How long do fresh mushrooms last?

The short answer

A gourmet mushroom cut this morning and kept cold and breathing lasts two to ten days depending entirely on the species. Pink and golden oyster are finished in three. Blue oyster, shiitake, lion’s mane and maitake give you five to seven. King trumpet and beech mushrooms will do seven to ten and often more.

A supermarket mushroom that has spent five days in a distribution chain has the same total window — it has just already used most of it before you got it. That is the whole difference between farm-direct and shelf product, and it is why the same species can seem to last a week for one person and two days for another.

The three things that decide it

1. Harvest date — the one you cannot fix

Nothing you do at home adds days back. A mushroom starts its clock at the cut. Ours are harvested Tuesday and Friday mornings and delivered the same day, which means day one at your door; the shelf equivalent is usually day four to six. Ask any seller when it was cut. If they cannot tell you, that is the answer.

2. Temperature — 34 to 38°F

Colder is better right down to freezing. The back of the bottom shelf, not the door. Every few degrees of warmth roughly doubles the rate of decay, which is why a mushroom left in a car for an afternoon in July can lose half its life in one trip.

3. Airflow — the one everybody gets wrong

Mushrooms respire after harvest. They give off moisture and carbon dioxide, and in a sealed bag that moisture condenses on the surface and becomes a film. Film becomes slime, and slime is the end. Paper, a perforated liner, or an open container with a dry towel laid over the top — all fine. A knotted plastic bag will cost you two to three days on any species.

The single most common cause of “my mushrooms went off in two days” is the plastic bag they came home in. Take them out of it the moment you get in.

How to tell where you are in the window

• Day one to three: dry to the touch, springy, edges intact, clean sweet smell. Good for anything, including raw garnish.
• Day four to six: slightly drier, maybe some edge curl or cap flattening. Perfect for searing, roasting and braising — arguably better, since there is less water to drive off.
• Day six onward: soft, darkening, possibly damp. Cook it long: duxelles, confit, stock, ragù, compound butter.
• Finished: slimy, sour or ammoniac, or visibly weeping. Compost it. More on the slime question here.

Getting to the far end of the range

Buy day-one product, take it out of plastic, keep it whole until you cook it, store it in a single layer in paper on the coldest shelf, and never wash it before storage. Do all five and most species will surprise you. Do none of them and every species behaves like a two-day mushroom.

Species-by-species numbers are in the shelf-life table, and if you want to stop thinking about it, the Share delivers a fresh box weekly so you are always at day one.

Common questions