How can you tell if mushrooms have spoiled?

Mushrooms are a delicious ingredient that can add flavor and texture to many dishes. However, like any fresh produce, mushrooms don’t last forever. Knowing how to tell if mushrooms have gone bad can help you avoid eating spoiled mushrooms and getting sick.

What are the signs of spoiled mushrooms?

There are a few clear signs that indicate your mushrooms have spoiled and are no longer safe to eat:

  • Slimy texture – Fresh mushrooms should feel dry and firm. A slippery, slimy texture is a sure sign they’ve gone bad.
  • Strong musty odor – Spoiled mushrooms will have a noticeably strong, unpleasant smell.
  • Discoloration – Look for excessive dark spots or color changes. A few small spots are normal, but excessive bruising can indicate spoilage.
  • Wrinkled appearance – Mushrooms that look very shriveled and wrinkled are past their prime.
  • Presence of mold – You may see fuzzy mold growing on old mushrooms. This is a very clear sign they’ve spoiled.

How can proper storage extend the shelf life of mushrooms?

With proper storage, fresh mushrooms can stay unspoiled for up to a week past their purchase date. Here are some storage tips to keep mushrooms fresher longer:

  • Keep them refrigerated – Cold temperatures slow the growth of bacteria and mold.
  • Store in a paper bag – Plastic traps moisture, which speeds up spoilage. Paper bags allow for more airflow.
  • Don’t wash until ready to use – Washing introduces extra moisture that causes mushrooms to spoil faster.
  • Don’t crowd the refrigerator – Too close contact also retains moisture. Spread them out.

How can you tell if dried mushrooms have gone bad?

With their low moisture content, dried mushrooms typically have a much longer shelf life than fresh. Properly stored, they can often last over a year past their purchase date before going bad. Signs that dried mushrooms have spoiled include:

  • Visible mold growth – Fuzzy mold growing on dried mushrooms means they’ve spoiled.
  • Loss of texture – Dried mushrooms that have gone soft or mushy have lost their signature chewy texture.
  • Strong musty or stale smell – Fresh dried mushrooms have an earthy, woodsy aroma. A strong off-putting odor indicates spoilage.
  • Change in appearance – Dried mushrooms that look very dull in color compared to when purchased may have gone bad.

What are some common types of mushroom spoilage?

There are a few main biological culprits that lead to mushroom spoilage. Being aware of these common causes can help you identify and avoid consuming spoiled mushrooms.

  • Bacterial growth – Bacteria naturally present on mushrooms can multiply rapidly in the right conditions, resulting in spoiled, slimy mushrooms with an unpleasant odor.
  • Mold – Various types of mold can grow quickly on old mushrooms, sometimes visible as fuzzy spots or discoloration.
  • Yeasts – Yeasts are fungus that ferment the natural sugars in mushrooms, making them alcoholic or slimy in texture.
  • Enzymatic browning – This natural chemical process causes discoloration and unappealing textures when cell damage occurs over time.

Can you eat mushrooms that have small dark spots?

It’s very common for fresh mushrooms to develop a few small dark spots or areas of discoloration. These are generally harmless, provided the mushroom still appears fresh otherwise. Spots that are less than a quarter inch in diameter are not an immediate cause for concern. However, mushrooms with numerous large spots or significant changes in color should be avoided.

Is it safe to eat mushrooms that smell musty?

A strong musty odor in mushrooms is generally an indicator they have spoiled and may not be safe to eat. However, it’s important to distinguish between a regular earthy mushroom smell and an actual foul, rotten odor. Fresh mushrooms can sometimes have a mild musty or damp soil type of smell that is normal. It’s the pungent, ammonia-like musty smell that signals spoilage.

What happens if you eat spoiled mushrooms?

Consuming spoiled, inedible mushrooms can make you sick. Symptoms generally occur within 30 minutes to 2 hours after eating them and can include:

  • Nausea and vomiting
  • Abdominal cramping
  • Diarrhea
  • Dizziness
  • Headaches
  • Lightheadedness
  • Chills
  • Cold sweats

In severe cases, mushroom poisoning can also cause liver damage. The toxic substances that cause these symptoms are byproducts created as the mushrooms break down and spoil.


Being able to identify spoiled mushrooms is an important skill for anyone cooking with fresh mushrooms at home. Follow simple storage guidelines to extend shelf life, and discard any mushrooms that show signs of spoilage like noticeable bruising, strong odors, excess moisture, or visible mold. When in doubt, remember the old adage – if it smells funky, it’s no longer good to eat! Following proper identification and handling practices can spare you an unpleasant bout of food poisoning.

Leave a Comment