Wood ear: the mushroom grown by the million in China that hangs on elder over here

Walk through a park in winter and look closely at old elder shrubs and you will see them: brown, rubbery flaps hanging from the branches like ears. Wood ear, Auricularia auricula-judae to science, is a common sight here that almost nobody picks. In China, Vietnam and Korea the same family is cultivated by the million, and anyone who has eaten a Chinese hot and sour soup has already tasted it. A portrait of an underrated mushroom you can grow yourself.

How do you recognise wood ear?

By shape and texture. The fruiting body is a gelatinous, translucent brown to reddish brown disc of three to ten centimetres, curved and folded like an ear, with fine velvety hairs on the outside and a smooth, veined surface on the inside. Wet, it is supple and springy like rubber; dry, it shrinks to a hard, dark flake that swells up again after rain. That last trait is why you can see it all year round, with mild wet winters as peak season.

Why elder in particular?

The Dutch and German names refer to a medieval legend: Judas was said to have hanged himself from an elder, and the fungus growing on elder became his ear. Biologically it is simpler: elder wood is soft, moist and rich, and wood ear is a specialist that breaks it down faster than almost any competitor. It also grows on beech, ash and occasionally other broadleaves, but on elder it is at home. Anyone with an old elder in the garden, or who can find one, already has the ideal log for this species.

How do you grow wood ear?

Like any wood mushroom: with plug spawn in fresh wood. The difference from shiitake and oyster is that the wood can be thin. Elder branches five to fifteen centimetres thick work excellently, and a log need be no longer than half a metre. Drill, tap in the plugs, seal with wax, then lay it in a damp shady spot; see our inoculation season piece for the basics. Wood ear is a fast species: on elder you often see the first ears within a year. After that a branch produces for two to three years, in waves after every wet spell, summer and winter alike.

A handy trait: a wood ear that dries out on the branch does not die. After rain it swells back up and keeps growing. So you can happily wait a week before harvesting, and even pick dried specimens off the branch to soak at home.

How do you eat it?

Not raw, and not like an oyster mushroom. Wood ear has little flavour of its own, and that is precisely its strength: it is there for texture, crunchy and slippery at once, and it absorbs the flavour of whatever it sits in. Sliced into strips through a stir-fry, in a hot and sour soup, in a Chinese salad with sesame oil and vinegar, or in a stew like a kind of noodle. Brief heating is enough. If you harvest it large and thick, cut away the hard attachment point and use the rest.

Storing

This is the easiest species of all to store. Thread the ears on a string or lay them on a rack, and within a few days they dry into hard flakes that keep for years in a jar. Soak for half an hour in lukewarm water before use and they are exactly as they came off the branch. In Asia, wood ear is traded almost exclusively dried, and that is no coincidence.

Who is this species for?

Anyone with an elder, anyone who loves Asian cooking, and anyone who wants a species that asks for little care and does something all year. It is not the mushroom to impress a birthday table, it is the mushroom that is simply always there. In our range it is also one of the few species that gives a serious harvest on thin pruning wood, which makes it especially suited to small gardens.