Fresh mushrooms in the fridge, how to store them and how long do they last?

Fresh mushrooms are highly perishable, and their texture and appearance can change as they sit in storage. Refrigeration slows those changes, but practical recommendations need some local context: official guidance in the UK and US does not always address exactly the same mushroom varieties or give the same type of storage advice.

A study published in LWT on 15 September 2026 helps explain why temperature matters. Researchers compared shiitake mushrooms stored at 5°C (41°F) with shiitakes held experimentally at −1°C (30.2°F), close to their freezing point. Near-freezing storage maintained better firmness and reduced browning. It does not mean that a household refrigerator should be set to −1°C/30.2°F.

Should fresh mushrooms be stored in the fridge?

Yes. In the United States, the FDA advises keeping mushrooms refrigerated at 40°F (4°C) or below. They can remain in their original packaging or be kept in breathable packaging such as a paper bag.

For packaged mushrooms, following the storage directions and date information on the label remains important. A refrigerator slows deterioration; it does not make fresh mushrooms indefinitely shelf-stable.

What does UK guidance say?

In the UK, official guidance is particularly important for Enoki mushrooms because of previous concerns involving Listeria monocytogenes. The Food Standards Agency advises consumers to keep Enoki mushrooms refrigerated at 5°C or below and to follow the instructions on the packaging.

The FSA also advises pregnant people, older people and those with weakened immune systems to be aware of the risk and recommends that vulnerable groups cook Enoki thoroughly. This is specific safety advice concerning Enoki mushrooms and should not be presented as evidence that every fresh mushroom poses the same risk.

Should mushrooms be kept in a paper bag?

For US consumers, the answer can be quite specific. The FDA says mushrooms can be refrigerated in their original packaging or breathable packaging such as a paper bag. Breathability is relevant because storage conditions can influence both deterioration and, particularly for wild-type mushrooms, the growth of harmful microorganisms.

For UK consumers, the official FSA source used here does not give the same general paper-bag instruction for all mushroom varieties. The appropriate advice is therefore to follow the storage directions supplied with the product, rather than importing a US recommendation and presenting it as UK guidance.

How long do fresh mushrooms last?

There is no single number that accurately describes the refrigerator life of every type of fresh mushroom. Species, initial freshness, packaging and temperature can all affect how quickly quality deteriorates.

This is one reason why package instructions matter. A time limit given for one mushroom or under one country’s guidance should not automatically be applied to button mushrooms, shiitakes, oyster mushrooms, Enoki and wild mushrooms alike.

A useful household strategy is therefore straightforward: buy an amount you are likely to use reasonably soon and check the mushrooms before cooking rather than assuming that refrigeration alone guarantees their condition.

How can you tell when mushrooms are deteriorating?

Appearance and texture provide useful clues. The FDA advises choosing mushrooms that are dry and firm and avoiding those that are bruised, discoloured or slimy.

Colour should not be interpreted in isolation, since mushroom species naturally differ. A combination of marked changes in appearance, loss of firmness and a slimy surface provides much more useful information than expecting every fresh mushroom to maintain one particular colour.

Why do mushrooms brown and soften?

Mushrooms remain biologically active after harvesting. Over time, changes within their tissues affect firmness, colour and overall quality.

The 2026 shiitake study investigated reactive oxygen species, or ROS, and the mushrooms’ antioxidant systems. Near-freezing storage reduced ROS accumulation while supporting antioxidant activity, and this was associated with better hardness and less browning.

Consumers do not need to monitor those biochemical processes themselves. The practical point is that storage temperature affects how quickly post-harvest deterioration progresses.

Does the new study mean mushrooms should be kept at −1°C/30.2°F?

No. The temperature was part of a controlled near-freezing experiment on shiitake mushrooms. Under the study conditions, shelf life increased from 16 days at 5°C to 32 days at −1°C.

The researchers describe the technique as potentially useful for the mushroom cold chain, including transport and post-harvest preservation. That is different from household refrigerator guidance.

At home, the appropriate approach remains much simpler: keep fresh mushrooms refrigerated, follow the package instructions and use local food-safety guidance, rather than attempting to reproduce an experimental near-freezing storage protocol.