Yes, morel mushrooms can make you sick, especially if they’re eaten raw or undercooked. While morels are prized by foragers and chefs, they contain naturally occurring toxins that break down only with thorough cooking. In 2023, a single restaurant in Bozeman, Montana served undercooked morels and caused 51 illnesses, three hospitalizations, and two deaths.
Why Raw Morels Are Toxic
Morels contain a compound called gyromitrin, a water-soluble, volatile toxin. When your body breaks gyromitrin down, it produces a metabolite called monomethylhydrazine (MMH), which is the actual substance that causes harm. MMH irritates the digestive tract directly, damages liver and kidney cells, and interferes with a key brain chemical called GABA. When GABA levels drop, the brain loses its normal braking system, which can lead to seizures in severe cases.
The good news: gyromitrin is destroyed by heat. Washing, boiling, and thorough cooking significantly reduce the toxin content and make morels safe to eat. The critical rule is simple: never eat morels raw, and don’t stop cooking them early.
Symptoms and How Quickly They Appear
Most people who get sick from morels experience gastrointestinal symptoms: nausea, vomiting, diarrhea, and abdominal pain. In the Montana outbreak, the median symptom onset was just one hour after the meal. These digestive symptoms account for the vast majority of reported morel poisonings and typically begin within one to three hours of eating.
Less commonly, morels can cause neurological symptoms. A study of 129 cases of neurological reactions to morels found that the most frequent complaints were tremor, dizziness, unsteadiness, and vision disturbances. These patients had typically eaten a large quantity of morels. About 67% of them also had gastrointestinal symptoms alongside the neurological ones.
In severe poisoning, particularly from very large doses or completely raw mushrooms, the consequences can include liver failure, kidney damage, seizures, and (rarely) death. The two deaths in Montana were linked to consuming uncooked morels.
The 2023 Montana Outbreak
The Bozeman restaurant outbreak is the most detailed case study of morel illness on record. Between late March and mid-April 2023, the restaurant served cultivated morels in a special sushi roll. Patrons who ate the roll were nearly 16 times more likely to become ill than those who didn’t. The CDC investigation found a clear dose-response relationship: people who ate more pieces got sicker.
Critically, the association with illness was much stronger on the day the morels were served uncooked compared to an earlier date when they underwent at least partial cooking. Meanwhile, California facilities that fully cooked the same cultivated morels reported zero gastrointestinal illnesses among their patrons. The takeaway was clear: cooking is what makes the difference.
Morels and Alcohol
Some people experience a distinct reaction when they eat morels and drink alcohol together. The symptoms resemble what happens with certain other mushroom species known to interact with ethanol: skin flushing, a sensation of lip swelling, palpitations, vomiting, and low blood pressure. In one documented group, six people who drank wine with their morels were the only ones at the table to develop these symptoms.
This reaction has been associated with specific morel species and doesn’t happen to everyone. But if you’ve ever felt unusually flushed or unwell after pairing morels with wine or beer, the mushrooms themselves may be the reason.
False Morels: A Dangerous Mix-Up
Foragers also face the risk of accidentally picking a false morel, most commonly a species in the Gyromitra genus. These mushrooms contain much higher concentrations of gyromitrin, ranging from 50 to 300 milligrams per kilogram in fresh specimens, enough to cause serious poisoning even in small amounts.
Telling them apart is straightforward once you know what to look for. True morels have a pitted, honeycomb-like cap and are completely hollow when sliced lengthwise from top to bottom. False morels have a brain-like, wrinkled surface rather than distinct pits, a solid or cottony interior (not hollow), and often develop a dark reddish color as they age. If you cut a mushroom in half and the stem is solid, it’s not a true morel.
How To Prepare Morels Safely
Start by cleaning your morels gently with a damp cloth or soft brush to remove dirt, debris, and insects. Don’t soak them in water for extended periods, as this degrades their texture.
Cook them thoroughly. Sautéing over medium heat until they’re fully softened and lightly browned on all sides is the standard approach. There’s no published minimum internal temperature specific to morels, but the principle is to apply sustained heat, not a quick sear. If you’re adding morels to a dish, cook them separately first rather than tossing them in raw at the end.
For storage, keep fresh morels refrigerated at 34 to 35°F, wrapped in a paper bag or waxed paper. Avoid plastic bags, which trap moisture and speed up deterioration. Fresh morels should smell earthy and clean. Toss any that have soft spots, bruising, or an off smell. If you’re drying morels for long-term storage, use stainless steel racks rather than other metals to avoid contamination.
Individual Sensitivity
Even properly cooked morels cause mild stomach upset in some people. This appears to be an individual sensitivity rather than a toxicity issue, since others eating the same batch feel fine. Eating a large quantity increases the likelihood of both gastrointestinal and neurological symptoms. If you’re trying morels for the first time, start with a small portion to see how your body responds before eating a full plate.