Which format to buy

Liquid, plate, slant, grain and pellets are not the same thing in different sizes. Each does a job.

Four ways to keep a mycelium alive

When two products carry the same species name and different prices, the difference is almost never “more mushrooms” or “fewer mushrooms”. It is the way the mycelium has been rested, and therefore what you can do with it on the day it arrives. Mixing these formats up is like buying flour and believing you bought the bread.

Liquid culture is a sugary broth in which mycelium has grown and then been broken into fragments small enough to pass through a needle. It is the fastest format for seeding a bag or a jar that already has a port. You do not see the colony. You trust the smell, the colour, and the person who made it. Ten millilitres are not “ten mushrooms”. They are inoculum for several kilos of grain, if you spread them.

A plate is the same species grown on a jelly, usually malt and agar, in two dimensions. You buy it because you can look at it. The leading edge tells you whether the colony is clean, whether it grows in ropes or in cotton, whether there is a sector to discard. From there you cut wedges and put them into grain. It is slower than a syringe and it gives you a control the syringe does not have. It is also the format that contaminates the moment you lift the lid in a draughty kitchen.

A slant is a tube of agar set at an angle, colonised, then put in the fridge. It does not fruit. You do not inject it. It is the library copy: it lasts for months, sometimes more than a year, and when you need it you revive it onto a fresh plate or into a broth. Buying it as a first purchase, if you do not already have plates and grain, means owning a fungus you do not yet know how to restart.

Sterilised grain, in a bag or a jar, does not yet contain your mycelium, unless it is labelled as colonised spawn. It is ready food, already moist and already pressure-cooked, waiting for an inoculum. Beech, straw or cereal pellets are a step further back: they are dry. You hydrate them, drain them and sterilise them yourself. They make sense if you have an autoclave. If you do not, you are buying a job that an already sterile bag would spare you.

Choosing from what you want to do this week

If your aim is a block of oysters, king oyster or shiitake within a month, buy a liquid culture and a substrate that has already been treated. The syringe goes in through the port. You open nothing sterile. It is the path with the fewest chances to get it wrong.

If you want to keep a genetic line, make several jars from one origin, or simply see whether what grows is white and clean, buy the plate. A lion’s mane plate, for example, lets you read the colony before you commit kilos of beech. Transfer to grain is a still-air gesture. It is not hard, but it is not the gesture for the first afternoon on which you only want mushrooms for dinner.

If you ferment, the slant is often the right format, because koji, tempeh and natto are restarted many times from a small reserve. There too the slant is not rice that has already been inoculated. It is the mother. For a kilo of rice for amazake you start from the slant and expand it, or you use a plate that has already grown.

A small oyster liquid culture is the inoculum format, made to go into a bag.

Pleurotus ostreatus Ostrica Pocket — Coltura Liquida 10ml€8,91

A lion’s mane plate is the format you read and cut from.

Hericium erinaceus – Piastra Petri Agar Fase Iniziale – Criniera di Leone€12,90

A white koji slant is a fridge reserve, not a meal.

Koji Bianco Aspergillus oryzae Slant Agar | Coltura Premium€17,90

Sterilised grain in a bag is food waiting for inoculum. It is not spawn until mycelium has run through it.

Grano Spawn Biologico Sterilizzato — 1 kg / 2 kg€12,00

What to look at when the parcel arrives

A healthy syringe is clear or slightly cloudy, with white strands or fragments. A sour smell, a green tint, a pressure that sprays brown liquid: do not inject it. A healthy plate starts at the centre and advances white. Green, black, or a wet film at the edge: do not open it. A slant tells you little until you revive it. If the cap is loose or the agar has melted and stinks, discard it sealed. A bag of sterile grain should be intact, without stains and without dark liquid in the bottom. Free water at the bottom is where bacteria win even if the rest looks fine.

Put everything in the fridge as soon as you can, away from the wall that freezes. Do not freeze it. Label anything you transfer, because in a month “the white bag” will not tell you whether it was an oyster or a king oyster, and the two are not fruited the same way.

A concrete case, so this does not stay theoretical

Suppose you want king oysters within a month, not a collection. You need a liquid culture of Pleurotus eryngii and a bag of beech that is already sterilised, or a rye-and-beech all-in-one. A plate of the same species is useful only if you want to see the colony before you commit the wood, or if you want several jars from it. A slant is useful if in six months you want to restart without ordering again. Raw beech pellets are useful only if you already have a pressure cooker and the patience to hydrate, drain and cook. Buying them “because they cost less per kilo” without that step means a bag of dry sawdust in the cupboard.

If instead you only want to know whether you like the work, one oyster in liquid and a kilo of sterile rye teach more than five different species arriving on the same day. The second species is bought when the first has colonised, not before. A fridge has a limit, and a mycelium forgotten behind the yogurt does not get better with time.

The format that does not exist

There is no format that saves you from understanding the difference between colonising and fruiting. The culture colonises. The substrate, once colonised, fruits if you change the air, the humidity and sometimes the temperature. Buying three syringes of difficult species, with no grain and no clean place to keep them, speeds nothing up. One species, a format matched to the gesture you know how to make, a substrate that suits that species: that is the choice that produces a harvest. The rest is a collection, and a collection is a legitimate project only if you know that it is a collection.