Mushroom Culture Library

Mushroom traceability: how culture lineage works

A grow log tells you what a block did. A culture library tells you why — which genetics, from which source, handled by which method. Here is what this tool records and what it lets you answer.

What traceability means on a small mushroom farm

Traceability is the ability to answer two questions about anything on your shelf: where did this come from, and what else came from the same place. In large food operations that is a certified system with audits behind it. On a small farm it is a discipline — a code written on every jar and an honest record of what came off what — and it earns its keep the first time a plate goes green, because you can quarantine exactly what is affected instead of guessing or dumping the lot.

Mycro is the small-farm kind. It keeps your own records, in your own browser, and does the two lookups for you in both directions. It is not a certified food-safety or compliance system and does not claim to be one: there is no auditor, no signature and no third party verifying anything. What it gives you is the chain itself, complete enough to act on and to show a buyer who asks where a batch came from.

The chain

Genetics enter the farm once and then get copied, over and over. Each copy is a chance to gain performance data — and a chance to let something in.

Tracking codes that carry the lineage

Every item gets a code derived from its parent, so the code alone tells you the chain: SHI-01 is a shiitake source, SHI-01-P1 is the first plate off it, SHI-01-P1-L1 the first liquid culture off that plate, and SHI-01-P1-L1-G2 the second grain jar off that LC. Write the code on the jar and the jar explains itself — no lookup needed.

Contamination traceback, in both directions

Mark anything contaminated and the library walks the chain for you. Downstream: every culture and every block descended from it, listed as at-risk so you can check or quarantine them before the problem spreads. Upstream: the parent it came from and its siblings — if those are clean, the contaminant entered at your step; if they're failing too, it came in earlier, possibly with the source. That distinction is the difference between fixing your technique and returning a bad lot. New to diagnosing what you're looking at? Read the contamination ID & prevention guide.

Because one container of grain spawn can inoculate several grow bags, grain spawn carries an optional count — so the traceback tells you how much is affected ("6 bags and 24 blocks"), not just which batch to go and look at. Grain goes into jars or into bags depending on how you work, so you pick the word when you log it and the tool uses yours everywhere after that. Run both and it counts them separately: "4 bags and 2 jars", never a total that hides the difference, because the number on the screen has to be the number you go and count on the shelf.

What is still running right now

A lineage tree tells you where things came from; it does not tell you what needs looking at today. Working cultures lists every live culture you haven't yet marked fully colonised, oldest first, with the day count running from the date you made it — so a plate you poured five weeks ago and forgot is at the top of the list rather than buried three levels down the tree. Typical windows (a petri dish or liquid culture in roughly 7–14 days, grain spawn in 14–21) are shown for orientation only. Nothing is ever called late against a published number: once you have recorded two cultures of the same species and type, the list starts flagging against your own pace instead, because how fast a culture runs is a property of your conditions, not of a textbook.

The grain-spawn shake

A jar or bag of grain spawn is not one event with a start and a finish. You inoculate it, let it run to roughly 20–30%, shake it so the colonised grain is redistributed through the rest of the jar, and then wait for it to hit 100% and go into grow media. The shake is the part you actually do, and the part it is possible to get wrong: too early and a thin culture may not recover, too late and you have gained little because the jar was nearly run anyway. So grain spawn carries the shake as its own dated milestone — a jar reads made, shaken on day 4, fully colonised in 12 days, 8 days after the shake. As everywhere else here, the day you should shake is never quoted from a book: shake two jars of a species and the working list starts telling you the day you usually shake, because that depends on your grain, your jar size and your room.

Finished work: archived, never deleted

When a run is done you want it out of the way, not gone. 🗄 Archive finished files away every used-up, discarded or contaminated culture in one go — out of the tree, the counts, the working clock and the strain table — while keeping every code, date and link exactly as it was, so a single click brings any of it back. You can archive one culture, or a whole source with its chain. Deleting a finished culture is the one thing that genuinely loses something: a used-up grain jar is still the parent of every block that came off it, so removing it breaks the traceback — flag a plate afterwards and it reports that nothing downstream was affected, which reads as good news rather than a missing link. For the same reason a sweep refuses to archive a finished culture that live work still hangs off, and says how many it kept and why.

Strain strength: what a plate tells you before the block does

Two things a grower already judges a culture on are how long it takes to fully colonise and how thick the growth is. Record either on any culture and they roll up per source, next to the loss rate of that lineage and the biological efficiency of the blocks that came off it — so a plate that ran fast and thick can be checked against what it actually yielded months later. Days to colonise are only comparable within a species (shiitake is naturally slower than oyster), so the library only ranks sources of the same species against each other.

Why record supplier and location at all

Two reasons, and both are practical. First, repeatability: if a strain performs you want to go back for more of exactly that, and if it doesn't you want to know not to. Second, chain of responsibility: if there is ever a question about what you sold and where it came from, the answer is a lookup, not an archaeology project. For a wild collection the location is the supplier — record the GPS or the address, because you can't re-order from a log you can't find again.

Your data stays on your device

This free library saves in your browser only — no account, no upload. It shares storage with the Grow Log, so backing either one up with ☁ Back up in the grow log covers both, and after that every change on this device syncs to your private link automatically. The paid Mycro app adds what a link can't: a real account you log into from any device, long-term history across seasons, cost per run, and multi-user access for a staffed farm.

Comparing tools? Most mushroom apps track blocks but not genetics, and the ones that track genetics don't do grow-ops maths. See the honest comparison of mushroom grow log apps.

Frequently asked questions

What is mushroom traceability?

Traceability is the ability to answer two questions about anything on your shelf: where did this come from, and what else came from the same place. In large food operations that is a certified system with audits behind it. On a small mushroom farm it is a discipline — a code written on every jar and an honest record of what came off what — and it earns its keep the first time a plate goes green, because you can quarantine exactly what is affected instead of guessing or dumping the lot.

Is there free mushroom traceability software?

Yes. The Mycro Culture Library is free, needs no account and runs in a browser. Log a source once, then add petri dishes, liquid cultures and grain spawn under it; each one takes a tracking code derived from its parent, so the code on the jar carries the lineage. Mark anything contaminated and it lists every culture, container and block descended from it, plus the parent and siblings it came from. It keeps your own records rather than acting as a certified food-safety or compliance system — there is no auditor and no third party verifying anything — and nothing leaves your device unless you choose to sync it.

What is mushroom culture lineage tracking?

Culture lineage tracking records the parent of every culture you make, so each petri dish, liquid culture, grain spawn jar and finished block can be traced back to the original source — the grower or supplier you bought it from, or the wild collection you took it from. It answers two questions a grow log alone cannot: which source and strain actually produces your best blocks, and, when a contaminant appears, which other cultures came off the same parent and need checking.

What should I record about a mushroom culture source?

For a purchased or gifted sample: species (scientific or common name), the supplier's batch number if they give one, the name and contact details of the company or individual, the date and time you received it, and your own assigned tracking ID. For a wild field sample: species, the location the sample was taken (GPS coordinates or address), date and time, and an assigned tracking ID. The supplier details matter for two reasons — you can go back for more of a strain that performs, and if there is ever a liability question you have a chain of responsibility.

How do I trace a mushroom contamination back to its source?

Mark the contaminated culture in your records, then walk the chain in both directions. Downstream: every culture and every block made from that culture is suspect and should be checked or quarantined. Upstream: look at its parent and at the other cultures made from that same parent — if they are clean, the contamination entered at your step; if they are also failing, it came in earlier, possibly with the source itself. The Mycro culture library does both walks automatically and lists the at-risk items.

Is there a free tool to track liquid culture and grain spawn?

Yes. The Mycro culture library is free and needs no sign-up. Log a source once, then add petri dishes, liquid cultures and grain spawn under it; each one gets a tracking code derived from its parent (for example SHI-01-P1-L1-G2) so the code itself shows the lineage. Grain spawn can be linked to a batch in the free Mycro grow log, which connects the culture chain to real yield and biological efficiency.

How do you measure the strength of a mushroom strain?

The two practical measures growers use on a petri dish are how many days it takes to fully colonise the plate and how thick the growth is — fast, thick, rhizomorphic growth indicates a vigorous strain, while slow or wispy growth suggests a weak or ageing culture. Those signals are only meaningful within a species, because shiitake naturally colonises far slower than oyster. The strongest confirmation comes later: the biological efficiency of the blocks grown from that culture. The free Mycro culture library records days to colonisation and growth thickness on any culture and shows them per source alongside the loss rate and the biological efficiency of the blocks descended from it.

Why track the number of grain spawn jars or bags?

One container of grain spawn usually inoculates several grow bags, so the count is what turns a contamination traceback from 'which batch' into 'how much'. If a liquid culture turns out to be contaminated, knowing that six bags of grain came off it, and how many blocks those bags went into, tells you the size of the problem and how much to quarantine. Growers do this in jars or in small bags depending on how they work, and the two are the same unit: one container holding one lot of grain. The free Mycro culture library stores an optional count on grain spawn, records whether it was jars or bags so it uses your own word, and totals the affected containers and blocks in its traceback, listing jars and bags separately if you run both.

When should you shake a jar of grain spawn?

Shake a grain spawn jar once the mycelium has colonised roughly 20 to 30 percent of the grain — enough growth that it can recover quickly, but early enough that redistributing it still saves you weeks. Shaking breaks the colonised grain apart and spreads those pieces through the rest of the jar, giving the mycelium many new starting points instead of one advancing front. Shake too early and a thin culture may not recover; shake too late and you gain little, because the jar is nearly run anyway. The right day depends on your grain, jar size and room temperature, so the useful number is your own: the free Mycro culture library records the shake as a dated milestone on every grain jar, alongside the day it was made and the day it finished, and once you have shaken two jars of a species it shows the day you usually shake rather than a figure from a book.

How do I clear finished cultures without losing the traceback?

Archive them rather than delete them. A used-up grain spawn jar is still the parent of every block that came off it, so deleting it silently breaks the contamination traceback — flag a plate later and it will report that nothing downstream was affected, which reads as good news rather than a missing link. In the free Mycro culture library, archiving a finished culture or a whole source takes it out of the tree, the counts, the working clock and the strain table while keeping every code, date and link intact, and one click brings it back. Archiving a finished culture that live work still hangs off is refused for the same reason.

How long should a petri dish, liquid culture or grain spawn jar take to colonise?

As a rough orientation, a petri dish or a liquid culture is usually fully colonised in about 7 to 14 days and a grain spawn jar in about 14 to 21 days, but the real answer depends heavily on species, temperature and how well the culture was agitated — shiitake runs far slower than oyster. That is why the free Mycro culture library treats those windows as orientation only and never calls a culture late against them: it lists every live culture with a day count running from the date you made it, and once you have recorded the finish date of two cultures of the same species and type it starts flagging a slow one against your own average instead of a published figure.

For legal culinary & medicinal mushroom cultivation only. Guidance here reflects common practice, not guarantees.