Button mushroom
Agaricus bisporus · A15 / U3 · v2.0.0
The largest commercial crop in India and the one this controller is least able to fake. Air temperature is not the control variable here — compost temperature is, and it runs one to two degrees above the air through the spawn run because the compost is generating its own heat. Without a substrate probe, this recipe is guesswork.
Spawn run
Advances after 14 days, or when you say so| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 24.0 °C | 23.5 °C – 24.5 °C | heater, cooler |
| Relative humidity | 92.0 % | 90.5 % – 93.5 % | humidifier |
| Carbon dioxide | 12,000 ppm | 9,500 ppm – 14,500 ppm | exhaust, intake |
| Light | dark | — | lights |
| Fresh air, minimum | 0.1 changes/hour | — | exhaust, intake |
High CO2 is deliberate and is not a fault. Agaricus runs its spawn through compost fastest in an atmosphere that would ruin an oyster crop.
Vapour pressure deficit at these targets: 0.24 kPa. That is what 92% humidity means at 24.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Casing
Advances after 8 days, or when you say so| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 23.0 °C | 22.5 °C – 23.5 °C | heater, cooler |
| Relative humidity | 93.0 % | 91.5 % – 94.5 % | humidifier |
| Carbon dioxide | 10,000 ppm | 8,000 ppm – 12,000 ppm | exhaust, intake |
| Light | dark | — | lights |
| Fresh air, minimum | 0.2 changes/hour | — | exhaust, intake |
The casing layer is not optional and is not a growing medium — it is a water reservoir and a microbial trigger. Peat and lime, kept wet, never allowed to dry through.
Vapour pressure deficit at these targets: 0.20 kPa. That is what 93% humidity means at 23.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Venting and pinning
Advances when you mark "pins observed", or after 6 days| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 17.0 °C | 16.5 °C – 17.5 °C | heater, cooler |
| Relative humidity | 90.0 % | 88.5 % – 91.5 % | humidifier |
| Carbon dioxide | 1,000 ppm | 800 ppm – 1,200 ppm | exhaust, intake |
| Light | dark | — | lights |
| Fresh air, minimum | 4.0 changes/hour | — | exhaust, intake |
The venting event. CO2 falls from ten thousand to one thousand over about two days while temperature drops six degrees. Do it faster and the casing dries and the pinset fails.
Vapour pressure deficit at these targets: 0.19 kPa. That is what 90% humidity means at 17.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Fruiting
Advances after 6 days, or when you say so| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 17.0 °C | 16.5 °C – 17.5 °C | heater, cooler |
| Relative humidity | 88.0 % | 86.5 % – 89.5 % | humidifier |
| Carbon dioxide | 1,000 ppm | 800 ppm – 1,200 ppm | exhaust, intake |
| Vapour pressure deficit | 0.23 kPa | 0.19 kPa – 0.27 kPa | humidifier, in advanced mode |
| Light | dark | — | lights |
| Fresh air, minimum | 4.0 changes/hour | — | exhaust, intake |
Grown in the dark. Light does nothing for Agaricus except open the caps early and cost you grade.
Vapour pressure deficit at these targets: 0.23 kPa. That is what 88% humidity means at 17.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Harvest
Advances when you mark "harvested", or after 3 days| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 17.0 °C | 16.5 °C – 17.5 °C | heater, cooler |
| Relative humidity | 86.0 % | 84.5 % – 87.5 % | humidifier |
| Carbon dioxide | 1,200 ppm | 1,000 ppm – 1,400 ppm | exhaust, intake |
| Light | dark | — | lights |
| Fresh air, minimum | 4.0 changes/hour | — | exhaust, intake |
Pick before the veil breaks. A broken veil is a different grade and a different price.
Vapour pressure deficit at these targets: 0.27 kPa. That is what 86% humidity means at 17.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Between flushes
Advances after 7 days, or when you say so| Signal | Target | Band | Switches on |
|---|---|---|---|
| Air temperature | 18.0 °C | 17.3 °C – 18.8 °C | heater, cooler |
| Relative humidity | 90.0 % | 88.0 % – 92.0 % | humidifier |
| Carbon dioxide | 1,500 ppm | 1,200 ppm – 1,800 ppm | exhaust, intake |
| Light | dark | — | lights |
| Fresh air, minimum | 2.0 changes/hour | — | exhaust, intake |
Water the casing back up. Three flushes is normal, the third is small, and a fourth rarely pays for the room it occupies.
Vapour pressure deficit at these targets: 0.21 kPa. That is what 90% humidity means at 18.0 °C — the figure the crop responds to, and the one a hygrometer cannot show you.
Alarms
These do not switch anything. They sit outside the control loop deliberately, so that a bug in the control logic cannot also silence the thing that wakes you.
- Air above 27 °C
- Air below 12 °C
- Humidity below 75%
- CO2 above 25,000 ppm
Have Claude read this for you
Optional, off by default, and it uses your own Anthropic API key rather than ours. It is shown the findings this page already computed and is told it may not invent a number — no setpoint, no threshold, no duty cycle. It ranks what matters and says it in two sentences. It is never in the control loop: nothing on your board waits on it, and if it is switched off everything here works exactly the same.
A room review sends about 2,000 tokens and gets back about 600 — roughly US$0.03, or under three rupees.
Get an API key Read the API docs
Paste the key under Settings → Mushroom in the dashboard. It is stored on this site and sent only to api.anthropic.com, only when you press the button.
These targets are derived from published literature, not measured on your substrate, your strain or your room. Treat any recipe you have not validated on your own farm as a hypothesis. The yield log exists so that your second run can correct your first. Literature-derived. Not yet validated on a farm.