Myths about spotting poisonous mushrooms

Plenty of folk “tests” surround mushrooms: drop a silver spoon into the pot, add an onion, see whether insects eat the mushroom. The trouble is that none of these methods work, and believing in them has cost people their lives. The most dangerous mushroom, the death cap, passes all these “tests” with ease.

Let's debunk the main myths about identifying poisonous mushrooms and look at what actually protects you from poisoning.

Myth 1. Silver turns black from poison

The most widespread legend: if you drop a silver spoon or coin in with the mushrooms and it darkens, the mushrooms are poisonous.

In reality, silver darkens from sulfur compounds found in many mushrooms regardless of whether they're edible. It will turn just as black from an ordinary field mushroom, and won't react at all to the deadly death cap. There's no connection to poison here at all.

Myth 2. Onion or garlic darkens next to a poisonous mushroom

A similar legend claims that an onion or garlic cooked with mushrooms turns brown if there's a poisonous one among them.

This isn't true either. The darkening is caused by an enzyme found in both edible and poisonous mushrooms. An onion can turn brown from a perfectly safe mushroom and stay pale next to a deadly one. The test shows nothing.

Myth 3. Insects and snails don't eat poisonous mushrooms

Many people are convinced that if a mushroom is wormy or has been nibbled by snails, it's definitely edible.

In fact, insect larvae and slugs happily eat mushrooms that are deadly to humans, including the death cap. Their bodies work differently. So snail marks prove nothing, and worms only spoil the mushroom.

Myth 4. Boiling or vinegar neutralizes the toxin

A very dangerous myth: supposedly any mushroom can be made safe if you boil it for a long time, pour off the water or add vinegar.

The toxins of the most dangerous mushrooms are heat-stable. Neither long boiling, nor drying, nor salting, nor pickling in vinegar destroys them. The brown rollrim remains dangerous despite soaking and boiling, and the death cap's toxin doesn't go away at all. More on the brown rollrim in a separate article.

Myth 5. Poisonous mushrooms are bitter or brightly colored

A common belief is that taste or color gives danger away: bitter and bright means poisonous, while pleasant and plain means safe.

This is false too. The death cap tastes pleasant, and the panther cap is a modest brown, not bright. Meanwhile, the bright red fly agaric gives itself away by its color. So neither taste nor color is a reliable signal.

What actually works

Instead of myths, here are a few rules that really keep you safe.

1. Accurate species identification. The only reliable way is to identify the mushroom with certainty. If you know it, pick it; if in doubt, leave it.
2. Checking the key features. A skirt on the stem and a sac at the base, white gills on an unfamiliar mushroom, and other morphological details.
3. Picking only species you know. Expand your list gradually, learning one mushroom at a time.
4. No on-the-spot “tests.” Silver, onions, tasting raw mushrooms: all of this is useless and dangerous.

The full set of guidelines is in our safe foraging rules, and an overview of dangerous species is in our guide to the poisonous mushrooms of Ukraine. If you suspect poisoning, call 112 or your local emergency number immediately and follow our first aid instructions.

Sources

• “Vyznachnyk hrybiv Ukrainy” (Field Guide to the Fungi of Ukraine; Kyiv, Naukova Dumka).
• Amanita pantherina on GBIF, the global biodiversity database.
• Fungi on MycoBank, the international fungal nomenclature database.
• Mushroom poisoning on Wikipedia.