In some Yunnan restaurants, between June and August, a scene occurs that anywhere else would be absurd: the pot arrives at the table, it is closed with a padlock and the waiter takes the chopsticks away. He comes back twenty minutes later.
It is not a marketing gimmick. It is a safety measure, and it answers a real, well-documented problem this province has with what is probably its most celebrated product.
01 A season that lasts three months
Yunnan is, without exaggeration, China's greatest mycological territory. It holds more than 900 mushroom species and supplies over 90% of the country's wild edible varieties. It is a direct consequence of its geography: six thousand metres of vertical range and isolated valleys produce very different forests.
But all that richness is concentrated in a narrow window. The season runs from June to August, and not out of custom: the mushrooms come up when the water arrives. In Kunming, those three months take 173.1, 215.7 and 195.9 millimetres of rain, more than half the annual total.
Which is to say: the worst season of the year for weather is the only good one for this. Anyone travelling in March, with 253 hours of sunshine, will have the best possible sky and will not see a single fresh mushroom at the market.
02 The mushroom that makes you see tiny people
The protagonist of this story is called Lanmaoa asiatica and is known locally as jian shou qing. It is a bolete, meaning it belongs to the same group as the mushroom eaten in Europe, and it is considered a delicacy.
What has made it famous outside China is what happens when it is eaten undercooked. The poisonings are chiefly neuropsychiatric, and in one series of patients 90% had hallucinations, along with common digestive symptoms.
And those hallucinations are remarkably consistent from one person to another. Patients describe vivid, colourful visions of tiny figures — little people, elves — jumping and dancing. In the medical literature the phenomenon has a name: lilliputian hallucinations.
03 The numbers
It is worth putting this in scale, because a curious anecdote hides a public health problem. Between 2010 and 2018, the province recorded more than 9,686 cases of wild mushroom poisoning, and the real figures may be higher because of under-reporting.
In 2025, Yunnan recorded 109 mushroom poisoning incidents, with two deaths. And the hospital attached to Yunnan University alone treats more than a hundred cases a year during the season.
Which is why the authorities do not treat it as a curiosity. The food safety office sends text-message warnings — mushrooms may be delicious, but do not try wild and unfamiliar varieties — and warning rhymes circulate that went viral, along the lines of red caps with white stems ending with everyone on the slab.
04 Why the padlock
Here is the detail that explains the opening scene. The difference between an excellent dish and a night in casualty is not in the species: it is in the cooking time. Jian shou qing must be boiled or steamed before being stir-fried over high heat.
The problem is human, not culinary: the mushroom smells good almost at once and the temptation to try it early is enormous, especially when it is cooked at the table. Hence some restaurants padlocking the pot and taking the chopsticks away for twenty minutes.
Seen that way, the padlock stops being picturesque and becomes what it is: a protocol. A place that applies it is saying it serves the product daily, knows the exact timing and has no intention of leaving the decision to the customer.
05 What science still does not know
The most puzzling part of this story is that nobody yet knows what produces the effect. The first thing ruled out was the obvious: it is not a psilocybin mushroom. It belongs to a completely different group from the known hallucinogenic fungi.
A team at the University of Utah sequenced the species' genome and found none of the genes needed to produce psilocybin or ibotenic acid, the two compounds that would explain such an effect in other fungi.
So the situation is this: a very consistent effect, described by thousands of people, with no identified compound. It is one of those things you assume has been solved until you look closely.
06 How to eat them without trouble
The practical conclusion is simple and it is not about giving up. Yunnan's mushrooms are one of the best gastronomic reasons to come to this province, and eating them in a restaurant that works with them daily in season is the normal, sensible thing to do.
What you should not do is the opposite: buy at the market out of curiosity and cook them yourself. The risk is not in the species, which is sold legally, but in not knowing how long it needs, and that is exactly the knowledge you cannot improvise.
And if you get the table with the padlocked pot, now you know what it means. They are not putting on a show or stretching out the wait: they are carrying out the one step of the process that actually matters. The twenty minutes are the dish.
Bjørn Christian Tørrissen In Mendoza there is a hot wind that comes down off the cordillera and shows up in the hospitals
Sebastian Fischer The Sicilian breakfast exists because someone used to carry snow down from Etna in summer
Simo Vichai