When is a mushroom ripe? The right harvest moment for each species

Of all the questions about grow kits, half are about when something will appear and the other half about when you may pick it. The second question is the important one, because almost everyone waits too long. In its last days a mushroom mostly grows in volume, not in flavour, and by the time it is at its biggest it is already past its peak. Here, species by species, is the sign to watch for. When in doubt: a day too early beats a day too late.

Oyster mushrooms: while the cap edge still curls down

A young oyster mushroom has a cap whose edge curls inward and downward. Once that edge flattens and then turns upward it is ripening, and a day later it starts dropping spores and turns chewy and dry. So harvest when the edge is just beginning to flatten. The pink oyster moves faster than any other: pick it while the fans are still thick and bright pink, often only five days after the first pins. Twist the whole cluster off at the base, not cap by cap.

Lion's mane and coral tooth: while the spines are still short and white

With lion's mane the spines are the clock. Half a centimetre to a centimetre long and pure white: harvest. Longer, and certainly once the tips turn yellow or pink: too late, and the flavour turns bitter. Do not wait for maximum size; a lion's mane left a day too long loses more flavour than it gains in weight. Cut the whole ball off close to the block. The same applies to coral tooth, only faster.

Shiitake: while the cap is still domed and the veil is just tearing

A shiitake is at its best while the cap is still domed, the edge rolled inward, and the veil between cap and stem is just beginning to tear. That is the donko form. Leave it and the cap opens into a flat disc with visible gills: still perfectly edible, but thinner, drier and less aromatic. On logs you pick daily in harvest season, and on a block you check twice a day, because a shiitake goes from domed to flat in one warm day.

Maitake: while the frond edges are still firm

Maitake is tricky, because it grows for weeks and there is no obvious day. Watch the edges of the fronds: as long as they are thick, firm and pale, it is still growing. When the edges turn thin and papery and start to dry or curl, you are already slightly late. Harvest when the rosette has stopped visibly growing for a couple of days and the edges are still intact. A maitake left too long smells unpleasant and turns tough, a waste of weeks of waiting.

Nameko, chestnut and pioppino: while the veil is still closed

With the clustering species the veil beneath the cap is the clock. Closed or just tearing: harvest. Open, with brown spores dusted over the cluster: too late. For nameko too late also means more slime and a softer cap, for chestnut a woody stem, for pioppino a flat, dry cap. All three are picked in clusters, at the base, in one go.

Wine cap: while the cap is still domed and wine red

Young, with a domed, dark red cap and pale gills, the wine cap is firm and delicious. Once the cap flattens, fades to yellowish brown and the gills turn purple-grey, it goes soft and watery and attracts slugs. In a warm, wet week that takes three days. Twist it off at the base; cutting leaves a stub that rots.

Velvet shank and wood ear: here you can wait

Two species where timing matters less. Velvet shank grows slowly in the cold and keeps well; harvest while the caps are still glossy and closed to slightly open. Wood ear can even be left to dry on the branch and picked later; young and supple tastes best, but too late hardly exists with this species.

Chicken of the woods: only the soft edge

Chicken of the woods is harvested not all at once but by the edge: as long as the outer centimetres are soft, juicy and bright yellow, cut those off and let the rest keep growing. Pale, dry and crumbly is past its date. This is the one species where you leave the fungus standing and harvest the young part.

The rules of thumb

• Edge down, veil closed, spines short: harvest.
• Edge up, gills visible, spores on the block: too late, but still edible.
• Yellow, brown, papery, slimy, smelly: past its date, off to the stock pot or the bin.
• Check daily in harvest season, twice a day in warm weather.
• Harvest the whole cluster at the base, never cap by cap.

Anyone who has once harvested an oyster mushroom on the day the edge just went flat, and fried it as in the frying piece, understands afterwards why this piece exists. The difference between good and too late is a single day, and that day is the whole difference between a grow kit that was "quite nice" and one you order again straight away.