How long does dehydrated mushrooms last?

Dehydrated mushrooms can last a surprisingly long time if stored properly. Here are some quick answers on the shelf life of dehydrated mushrooms:

Quick Answers

– Unopened dehydrated mushrooms can last 1-2 years past the printed expiration date if stored in a cool, dark place.

– Once opened, dehydrated mushrooms last 6-12 months if stored in an airtight container in the pantry.

– Look for signs of moisture, mildew, off odors or flavors before using dehydrated mushrooms past the expiration date.

– Rehydrating and cooking mushrooms does not extend their shelf life. Use reconstituted mushrooms within a few days.

– Freezing extends the shelf life of dried mushrooms for 2-3 years.

How Are Dehydrated Mushrooms Made?

Dehydration removes the moisture from fresh mushrooms using hot air or the sun. This preservation technique halts microbial growth and other deterioration, allowing the mushrooms to be stored for extended periods.

Commercial dehydrators blow 180-200°F air over the mushrooms, drying them out completely within 6-8 hours. Some use lower temperatures, closer to 120°F, which can take 12-24 hours to fully dehydrate mushrooms. Either way, the water activity is reduced below 0.85, making it impossible for bacteria, yeasts and molds to thrive.

Vacuum packaging or storing in oxygen-free containers further prevents oxidation and deterioration. With an intact moisture barrier, properly dehydrated mushrooms remain unspoiled during prolonged storage.

Shelf Life of Unopened Dehydrated Mushrooms

When stored properly, unopened commercially packaged dried mushrooms stay fresh for:

  • 1-2 years past the printed expiration date. The key is cool, dark storage to prevent temperature and light-induced breakdown.
  • Up to 5 years when vacuum sealed with an oxygen absorber. Oxygen accelerates decomposition.

Signs that dried mushrooms have spoiled while still sealed include condensation inside packaging, visible mold, foul odors, and loss of color or texture. Discard if any sign of moisture, mildew, or unpleasant aromas are noticed.

Opened Dehydrated Mushrooms Shelf Life

Once exposed to air, dehydrated mushrooms have a shorter shelf life of:

  • 6-12 months in an airtight container in the pantry
  • 4-6 months in a resealable plastic bag

The shelf life decreases because air carries moisture that can lead to caking, mildew growth, and other undesirable changes. Storing in an airtight glass or plastic container prevents moisture absorption while keeping out insects.

Maximizing Shelf Life After Opening

Follow these tips to maximize the shelf life of dehydrated mushrooms after opening:

  • Transfer to an airtight container or jar. Mason jars work great.
  • Squeeze out excess air and seal the container tightly.
  • Store in a cool, dry place away from direct light.
  • Check periodically for moisture and other signs of spoilage.
  • Use a clean, dry utensil each time to avoid introducing moisture.
  • Re-seal container tightly after each use.

Leftover Rehydrated Mushrooms

Rehydrating dried mushrooms does not prolong their edibility. Follow these guidelines for leftovers:

  • Refrigerate reconstituted mushrooms in an airtight container for up to 5 days.
  • The texture suffers with prolonged refrigeration.
  • Discard mushrooms if slimy, discolored or foul smelling.
  • Frozen cooked mushrooms keep for 2-3 months in an airtight freezer container.

For best quality, plan amounts to avoid leftovers. Use reconstituted mushrooms promptly in recipes rather than trying to extend storage.

Freezing Dehydrated Mushrooms

Freezing unopened dried mushrooms extends the shelf life. Frozen mushrooms remain unspoiled for:

  • 2-3 years at 0°F or below
  • 6-12 months in the freezer compartment above 0°F

To freeze, place dried mushrooms in freezer bags or airtight containers, removing excess air. Avoid moisture absorption by lining containers with plastic wrap or foil.

Thaw frozen mushrooms overnight in the refrigerator before using. They regain their original texture after rehydrating in recipes.

Dehydrated Mushroom Varieties & Shelf Life

The dehydration process preserves all types of mushrooms. Shelf life varies slightly by variety when properly stored:

Mushroom Unopened Shelf Life Opened Shelf Life
Shiitake 2 years 12 months
Oyster 18 months 9-12 months
Portobello 2 years 6-9 months
White button 2 years 6-12 months
Maitake 18 months 6-9 months
Porcini 2 years 9-12 months
Morel 2 years 6-9 months
Chanterelle 18 months 6-9 months

Mushroom variety affects the initial shelf life to some degree, but proper storage has a greater overall impact. Follow the storage guidelines outlined above and dried mushrooms of any variety can stay fresh for many months post-opening.

Storage Temperature & Humidity

Temperature and humidity are two critical factors for optimizing dehydrated mushroom shelf life. Ideal conditions are:

  • 50-60°F temperature – Colder is even better for long-term storage. Refrigeration can extend shelf life slightly.
  • 60-70% relative humidity – Excess moisture causes mushrooms to reabsorb water and deteriorate faster.

Store in the pantry or any cool, dry place that maintains these conditions. Warm, humid environments shorten the shelf life considerably.

Signs Dehydrated Mushrooms Are Bad

Watch for these signs that dried mushrooms have spoiled and should be discarded:

  • Moisture or caking – Absorbed moisture causes mushrooms to rehydrate and decay.
  • Mold growth – Fuzzy mold spots indicate spoilage.
  • Discoloration – Oxidation causes color changes from bright white to yellow, gray or black.
  • Slimy texture – Slime signals bacterial or yeast growth.
  • Off odors – Mushrooms smell earthy when fresh but rancid or rotten when spoiled.
  • Loss of flavor – Stale or cardboard taste.

Trust your senses. Discard mushrooms at the first signs of moisture, mold, foul odor, unappetizing appearance or strange flavors.

Frequently Asked Questions

Do dehydrated mushrooms need to be refrigerated?

Refrigeration is not required to extend the shelf life of unopened dried mushrooms. An unopened package can be stored in the pantry for up to 1-2 years past the printed expiration date. Refrigeration can add a few months at most.

Can you vacuum seal dried mushrooms?

Yes, vacuum sealing dried mushrooms is an excellent way to prolong freshness, especially if used with an oxygen absorber. Vacuum sealing provides an airtight environment that protects against moisture, air, light, insects and other contaminants during storage.

How long do dried morel mushrooms last?

Dried morel mushrooms keep for about 2 years unopened or 6-9 months opened if stored properly in a cool, dark place. Morels are more perishable than many other mushroom varieties due to their honeycomb structure which is susceptible to moisture absorption and microbial growth, so maximum storage times may be less.

Do dried mushrooms need to be soaked before cooking?

It is not entirely necessary but soaking makes dehydrated mushrooms more palatable in most recipes. Soaking reconstitutes them to a tender, plump texture and improves flavor. Most recipes call for soaking 15-30 minutes or up to 1 hour for larger mushrooms.

Can you freeze rehydrated mushrooms?

Yes, you can freeze reconstituted mushrooms for 2-3 months. Blanch in boiling water for 3-5 minutes before freezing to stop enzymatic activity. Allow to cool, then transfer to freezer bags or containers, removing excess air. Frozen cooked mushrooms are best for casseroles, soups and stews rather than eating raw.

Can you freeze dried mushrooms without cooking them first?

Dried mushrooms can be frozen without cooking. Place them in airtight freezer bags or containers, seal tightly and freeze for 2-3 years at 0°F. This preserves texture well for rehydrating and cooking later. Allow to thaw overnight in the refrigerator before using.

Do dried mushrooms need to be soaked in hot water?

Hot water is not strictly needed but often recommended for rehydrating dried mushrooms faster. Some minerals and flavors only dissolve in hot water. Use 130°F to 140°F hot water for 15-30 minutes. But cold water also works, just requiring a longer soaking time of up to 1 hour.


With proper storage techniques, dehydrated mushrooms can remain unspoiled for many months, or even years. Unopened packages last for 1-2 years past the printed date. Once exposed to air, dried mushrooms keep for 6-12 months if stored in an airtight container in a cool, dry place.

Check for moisture, odor and color changes to determine if they are still usable. Discard at the first signs of spoilage. With careful storage and handling, dehydrated mushrooms can be enjoyed long after their purchase date.

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