The Gypsy Mushroom: How to Identify It and Why Caesium Matters

The gypsy mushroom (Cortinarius caperatus, formerly Rozites caperatus) is a gilled mushroom of coniferous and mixed forests. Its folk names vary from region to region: in Ukrainian it is kovpak or panchishka (“little stocking”), and Russian-language atlases call it kurochka (“little hen”) or turok. Just bear in mind that the folk name kurochky is given to other mushrooms as well, so the name alone guarantees nothing. It is safer to recognise the gypsy mushroom by its features.

It belongs to the webcaps, a genus that includes deadly poisonous species. But the gypsy mushroom is easy to tell apart from them, and it is a good edible mushroom. It has two traits that are rarely written about: it strongly accumulates radioactive caesium and mercury.

How to recognise the gypsy mushroom

• Cap 7–14 cm, straw-ochre, in the centre covered with a silvery frosty bloom, as if dusted with flour. Towards the edge the cap is wrinkled, with a broad bump in the middle.
• Gills pale clay-coloured at first, later rusty brown.
• Stem 6–12 cm, whitish.
• A true membranous ring, above the middle of the stem, that does not disappear with age. This is the key feature: the other webcaps have only a cobweb-like veil instead, which leaves rusty threads behind.
• Spore print rusty brown.
• Smell faint and indistinct.

It grows from August to October in coniferous and mixed forests on acidic soils, under pine and spruce, alongside bilberry and heather. In Ukraine it is found most often in Polissia, the northern forest belt of Ukraine, and in Prykarpattia, the Carpathian foothills.

Radiocaesium and mercury: what you should know

The gypsy mushroom is one of the mushrooms that accumulate radioactive caesium-137 most strongly. In Poland its caps were found to contain up to 18 000 Bq/kg dry weight in 2002 and still around 11 000 Bq/kg in 2008. Among the webcaps in studies from Italy and Poland, it was the gypsy mushroom that accumulated the most caesium. The authors of the Polish study estimated that in 1996–2010 a person who ate these mushrooms often took in more caesium than EU limits allow.

This matters for Ukraine, because the gypsy mushroom's main habitat there is Polissia, part of which was affected by the Chornobyl accident. What you can do:

• do not pick gypsy mushrooms in areas with radioactive contamination, and if you do not know the state of your forest, have the mushrooms tested at a radiological monitoring laboratory;
• boil them and pour the water away. In the same study, blanching with the cooking water poured away noticeably reduced the amount of caesium in the dish compared with frying or stewing.

The gypsy mushroom also readily accumulates mercury, even in clean forests. So even where radiation is not a problem, it is best not to eat it every day throughout the season.

What not to confuse the gypsy mushroom with

Poisonous webcaps. The fool's webcap and the deadly webcap contain orellanine, which destroys the kidneys. The first symptoms appear very late — often one to two weeks after the meal, and there is no antidote. Here is how to tell them apart: they have no membranous ring, their cap is orange-rust, and they often grow in moss. All webcaps have a rusty spore print, so a spore print will not separate them from the gypsy mushroom — look at the ring. Why it is better not to pick webcaps at all, we explained in the article webcaps: how to recognise the genus.

Death cap. You might think they have little in common, but a young gypsy mushroom with its ring is sometimes confused with exactly this one. The difference: the death cap has white gills, a white spore print, and the base of its stem sits in a baggy volva. The gypsy mushroom's gills turn brown, and it has no volva. Death cap poisoning begins 6–24 hours after eating and attacks the liver. Doctors in Ukraine's Ternopil region reported that amanitas there are often confused precisely with the gypsy mushroom, so it is worth turning every mushroom over and checking the gills and the stem base.

Hebeloma and Inocybe species. They also have a brown spore print, but they have no membranous ring. Poison pie, for example, has a sticky cap and smells of radish.

The basket rule: frosty bloom on the cap + a true membranous ring + gills that turn brown — it is the gypsy mushroom. No ring — not a gypsy mushroom.

How to cook the gypsy mushroom

The gypsy mushroom is good fried, stewed and pickled. But given the caesium, the best approach is to boil it first, pour the water away and only then fry or stew it. Young mushrooms with firm caps taste better than old ones.