Winecork brittlegillRussula adusta

The winecork brittlegill (Russula adusta) is edible but poor. In Eastern Europe it is eaten only salted, after soaking or boiling, and British guides rate it as edible but of low quality. It is easily mixed up with the blackening brittlegill (Russula nigricans), and the quickest way to tell them apart is to break the flesh. In the winecork brittlegill it turns faintly pink over about half an hour, then pale smoky grey. In the blackening brittlegill it quickly turns red and soon goes coal black.

What does it look like? It's a large, firm mushroom with no milk. The cap is 5–15 cm across, occasionally up to 20, convex at first, then flattened with a central dip, and almost funnel-shaped in old specimens. Young caps are dirty white or greyish buff, later grey-brown or smoky brown, and dark brown with age. In damp weather the cap is slightly sticky and shiny. The gills are white, then greyish, and darken where pressed. The stem is thick, hard and paler than the cap, and it also darkens when handled. The spore print is white. And there's the smell: noticeable and musty, like an old wine cask, which is where the English name comes from.

It grows under pines on acid, often sandy soil, and in the mountains also under fir and spruce, alone or in small groups. It fruits from summer into mid autumn, most often in late summer and early autumn, and it is uncommon. It is found across Europe, Britain and Ukraine included.

Can you eat the winecork brittlegill? Yes, but it isn't worth much. Russian and Soviet guides place it in their lowest edible category and advise soaking or boiling it, pouring the water away and then salting it; it turns black in the brine. Roger Phillips calls it edible but poor, while the English Wikipedia article lists it as poisonous, able to upset the stomach. We found no recorded poisoning by this species itself, but that doesn't mean none has happened. If you feel sick, have stomach pain or start vomiting after a mushroom meal, call 112 (999 in the UK).

How is it different from the blackening brittlegill? Apart from the flesh, by the cap and the habitat. The blackening brittlegill has a dry, matt cap, can be even larger, and grows in both broadleaf and conifer woods. The winecork brittlegill has a greasy, shiny cap and sticks to pine and fir. Gill spacing is no help, as sources describe it differently. The naming doesn't help either: Index Fungorum and GBIF treat the name Russula nigricans as a synonym of Russula adusta, and since 2024 the English Wikipedia covers both mushrooms in one article. In field guides they are two separate species, and so they are here.

Other look-alikes. The menthol brittlegill blackens at once when cut, with no pink stage, and its gills taste of menthol. The milk-white brittlegill stays white or cream and its flesh doesn't turn grey. The ugly milk cap, called «chernushka» in Russian, a name sometimes also given to this species, has an olive-brown cap, grows with birch and oozes white, acrid milk when broken; brittlegills have no milk.

Western guides are wary of all the brittlegills that redden and blacken because of an Asian relative, Russula subnigricans. It is deadly: within hours of a meal it causes vomiting and muscle pain, followed by muscle breakdown and kidney and heart failure. Poisonings have been recorded in Japan, Korea, China and Taiwan, and the species has not been found in Europe. If you travel in East Asia, don't pick brittlegills there by the features you know from home.