Harvest

The window is narrower than most people expect, and it closes faster than it opens. Mushrooms gain most of their final size in the last 24–48 hours, and then pass their best within about twelve.

The general rule: slightly early beats slightly late, every time.

When

The signal is species-specific but the principle is universal — harvest at or just before the point where the mushroom is about to release spores.

Species	Harvest when
Oysters	Cap edges still curled under, before they flatten and turn up
Lion’s mane	Still white, spines long, before any yellowing
Shiitake	Cap 60–70% open, veil just broken
King oyster	Cap still tight and domed, before it flattens
Wine cap	Veil still intact or just breaking
Reishi	White growing edge has stopped advancing and gone red

For gilled species generally: look at the cap margin. Curled under means still growing. Flat means ready. Turned up means you are late and it is sporulating.

Why late is worse than it looks

Spore drop. A heavily sporulating flush coats the block and the room. On the block it feeds contaminants; in the room it sensitises you over time. Oysters in particular can leave a visible layer overnight.

Texture and shelf life. Over-mature mushrooms are tougher, more fibrous, and degrade far faster in the fridge.

Yield, counterintuitively. Mushrooms lose water and begin breaking down their own tissue once mature. A day past ideal frequently weighs less, not more.

The next flush. A block that has spent energy on a full spore release has less left for flush two.

How

Take whole clusters, not individual mushrooms. Twist and pull at the base. Picking selectively leaves wounds and dying tissue, which is the main route to contamination between flushes.

Get every stem butt out. All of them. A stub left in the substrate is dead tissue in a warm humid place, and it is where cobweb mold starts.

Cut flush for species that don’t detach cleanly — lion’s mane, reishi. Clean knife, wiped with alcohol between blocks.

Pull aborts at the same time.

Clean hands. Not sterile; clean.

Immediately after

• Let the surface dry for about a day. A dry wound recovers; a wet wound invites bacteria and mold.
• Reduce misting slightly for that period.
• Do not soak the block straight away, whatever else you do — a wounded surface plus non-sterile water is a bad combination.

Storing

Do not wash them. Mushrooms absorb water readily and washed mushrooms both store worse and refuse to brown properly in a pan. Brush off debris.

Paper bag in the fridge. Plastic traps moisture and they go slimy within days. A paper bag lets them breathe.

Expect 5–10 days for most species. Oysters are on the short end; king oyster and shiitake keep noticeably longer.

Drying is the best long-term option. Slice to even thickness, dehydrate at around 50°C until cracker-dry — snapping, not bending — and store airtight with a desiccant. Dried mushrooms keep for a year or more, and shiitake in particular is widely held to improve.

Freezing works if you cook them first. Raw frozen mushrooms turn to mush on thawing because ice crystals rupture the cell walls.

Yield expectations

First flush is typically 50–70% of total lifetime yield. Plan around that rather than around the biggest number you have read.

For a 5 lb supplemented sawdust block:

• First flush: 1–1.5 lb
• Second: 0.5–0.8 lb
• Third: 0.2–0.4 lb, if you get one

Work it out for your own grows with the biological efficiency calculator — it is the only honest way to compare a straw grow with a sawdust grow.

Next

After harvest, the block can usually be pushed for another flush.