Paper bag or container?

Why plastic fails

A harvested mushroom is still alive. It respires — takes in oxygen, gives off carbon dioxide and water vapour — for days after it is cut. Seal it in plastic and that vapour has nowhere to go: it condenses on the cap, forms a continuous film of water, and that film is a perfect medium for the bacteria that produce slime. Sealed plastic does not preserve mushrooms, it incubates them.

This is the single most common storage mistake and it costs two to three days on every species.

The ranking

1. Open container with a dry towel over the top — best

A shallow dish, a sheet pan, or a lidded container with the lid off, mushrooms in a single layer, a dry kitchen towel or paper towel laid loosely over the top. Air moves, excess moisture is wicked into the cloth, and nothing presses down on the caps. Swap the towel if it feels damp. This is what we do in our own cold room.

2. Paper bag, loosely folded — very good

The classic answer, and it works: paper breathes and absorbs surface moisture. Two rules — fold the top over rather than sealing it, and do not overfill, because mushrooms at the bottom of a stuffed bag get crushed and bruise. Ideal for a fridge with no space.

3. The vented punnet or box it came in — good

If it arrived in a perforated or open box, leaving it there is fine, provided you take off any plastic film. Do not stack anything on top.

4. Sealed container with the lid on — poor

Better than a knotted bag because there is more air volume, but the moisture still has nowhere to go. If it is all you have, leave the lid slightly ajar and add a dry paper towel.

5. Knotted plastic bag — worst

Two days, maybe three, and then slime.

If your mushrooms came home in plastic, take them out before they go in the fridge. That one action is worth more than everything else on this page.

Where in the fridge

The coldest part, which is almost always the bottom shelf at the back — not the door, not the crisper drawer if that drawer is set to high humidity. Away from anything with a strong smell; mushrooms pick up odours readily. And in a single layer if you can, because weight from above bruises caps and a bruise is where spoilage starts.

What about the humidity question

Mushrooms want cold and dry-ish air, not humid air. A high-humidity crisper setting works against you here — that is a setting designed for leafy greens. If your drawer has a vent slider, open it.

Species-specific numbers are in the shelf-life table; the commercial version of all this is on the walk-in page.

Common questions