Votre kit de culture de champignons ne produit pas de champignons ? Voici comment identifier le problème et y remédier
A grow kit that refuses to pin is the single most common worry we hear from growers, and in the large majority of cases the kit is perfectly fine. Most “stuck” kits are simply early, or sitting in conditions that are slightly off on one of four variables. This guide walks you through the exact diagnostic order an experienced grower would use: confirm timing first, then check the four fruiting conditions, then rule out contamination, and only then attempt to revive the kit.
Work through it in order. Do not jump straight to “reviving” a kit that is actually just three days early.
First, is your kit actually stuck?
Before changing anything, confirm your kit is genuinely behind schedule rather than just early. Patience is the most underused fix in cultivation.
After you start a kit under good conditions, the first pins (tiny mushroom primordia, often as small white bumps) typically appear within roughly 7 to 14 days, depending on the strain and your room conditions. Colder rooms push this later. A kit that has not pinned on day 5 is not a problem; it is normal.
Use this as a rough mental model:
- On time / lazy: no pins yet, but still within about a week of the normal first-pin window for your strain. Keep following the instructions and check daily. Do nothing else.
- Unhappy: no pins up to roughly 14 days past the expected window. Almost always a conditions problem (temperature, fresh air or light). Fix the conditions below.
- Sleeping: no pins more than about three weeks past the expected window, with no visible contamination. This is when a wake-up procedure is justified.
If you are still inside the lazy window, stop here and wait. If not, continue.
The Four Conditions Every Kit Needs to Fruit
Fruiting is triggered by a combination of cues, not a single one. When a fully colonised kit (the substrat is covered in white mycelium) will not pin, the cause is nearly always one of these four. Check them in this order.
1. Temperature
This is the most common reason a colonised kit stalls. Most Psilocybe cubensis kits fruit best at roughly 20 to 28 °C, with around 23 °C as the sweet spot. Below approximately 18 °C, the mycelium slows dramatically or goes dormant. Temperatures that are too high can encourage bacterial growth and cause the substrate to dry out more quickly.
Measure the temperature as close to the kit as possible, not elsewhere in the room. If you use a heat mat, never place the kit directly on it. Instead, use a buffer such as cardboard, cork, or a small rack underneath, as direct contact can overheat the base of the substrate.
2. Fresh Air Exchange (FAE)
Mycelium consumes oxygen and releases carbon dioxide (CO₂), just like humans do. High CO₂ levels are one of the most common reasons a kit refuses to pin, or produces long, thin mushrooms with tiny caps. If your mushrooms are growing tall and spindly, insufficient fresh air is usually the cause.
The solution is to improve airflow without drying out the grow kit. Only open the grow bag as instructed by the manufacturer and continue using the original bag supplied with the kit, as it is designed to balance humidity and gas exchange. Opening the bag too often or for too long can dry out the surface and increase the risk of contamination. Fresh air and humidity must remain in balance.
3. Humidity
Mycelium absorbs moisture from the surrounding air, not just from the substrate. If the surface dries out, pins can quickly abort. The goal is to maintain a humid microclimate without allowing water to pool on the substrate. Condensation on the inside of the grow bag is normal and generally a good sign.
If the surface appears dry, create a simple humidity tent by covering the kit with a clear plastic bag containing a few small ventilation holes. Mist the inside of the bag rather than spraying the substrate directly. Light misting two to three times per day is usually sufficient. Never allow standing water to collect on the surface, as this weakens the substrate and promotes contamination.
4. Light
Although fungi do not photosynthesise, mushrooms use light as a cue for direction and fruiting. Place the grow kit in indirect daylight and maintain a normal day-night cycle. A shelf or table in a naturally lit room is ideal.
Avoid direct sunlight, which can overheat the kit, dry out the substrate, and create large temperature fluctuations. Complete darkness should also be avoided, as it suppresses one of the environmental triggers required for fruiting.
Reading Your Kit: Healthy Mycelium Versus Contamination
Before attempting to revive a grow kit, rule out contamination. A contaminated kit cannot be recovered and should not be reused. Fortunately, many growers mistake healthy mycelium for mould.
- White, fluffy or thread-like growth: This is healthy mycelium. It may resemble cotton wool or develop a fuzzy, cauliflower-like appearance shortly before pinning.
- Yellow, amber or brown liquid droplets: These are metabolites, sometimes referred to as “mushroom pee.” They are harmless and often indicate that the substrate is mature and preparing to fruit.
- Blue, green, black or grey patches: Coloured fuzzy growth is usually mould contamination. A kit with established green or black mould, or one that develops a sour, musty or unpleasant smell, should be discarded immediately. Contact your supplier for assistance.
A simple rule of thumb: white and odourless is generally healthy, while coloured growth or unpleasant smells indicate contamination. If you are unsure, take a clear photograph and contact support before handling the kit further, as disturbing a contaminated substrate can spread spores.
How to Wake a Sleeping Kit
Only attempt these methods if your grow kit is genuinely in the “sleeping” stage (well beyond its expected pinning window) and you have confirmed there is no contamination present. Try one technique at a time, give it several days to work, and only move on to the next method if necessary.
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Re-check the four fruiting conditions.
Temperature, humidity, fresh air, and light are responsible for most delayed grow kits. Correct any issues and wait three to four days before taking further action. -
Cold shock.
A temporary drop in temperature can sometimes trigger pinning. Place the closed grow kit in a refrigerator (never a freezer) for approximately 12 hours, then return it to normal fruiting conditions. This mimics the seasonal temperature changes that often trigger fruiting in nature. -
Increase fresh air exchange.
Provide a few additional controlled air exchanges each day, following the instructions supplied with your grow kit. This helps remove accumulated CO₂ and signals to the mycelium that conditions are suitable for fruiting. -
Rehydrate the substrate if allowed.
Some cake-style grow kits respond well to careful rehydration. Only perform this step if it is specifically recommended in the manufacturer’s instructions. Always use clean water and practice good hygiene, as rehydration increases the risk of contamination.
Be patient after applying a recovery method. Once pinning begins, mushroom growth can accelerate rapidly, and a delayed kit can still produce an excellent harvest.
Strain Timing: Why Some Kits Take Longer
Not all mushroom souches develop at the same pace. A slower-growing strain is often mistaken for a failed grow kit when it is simply following its natural timeline.
- Standard Psilocybe cubensis strains such as Golden Teacher, B+, and Mexican are generally beginner-friendly and typically pin within the normal timeframe.
- Hybrid strains such as Jack Frost and similar genetics often require an additional 7 to 14 days before pinning compared to standard cubensis varieties.
- Penis Envy genetics are well known for their slower development and can sometimes take four weeks or longer before producing pins.
If you are cultivating a slower strain, adjust your expectations accordingly before assuming there is a problem with the grow kit.
When to Stop and Request a Replacement
In some cases, the issue lies with the grow kit itself rather than the growing conditions. Contact your supplier if any of the following situations apply:
- The kit arrived with visible green, black, or otherwise coloured mould.
- The substrate has a sour, musty, or unpleasant smell.
- The substrate never became colonised and shows little or no white mycelium growth.
- The kit remains inactive long after its expected fruiting window despite correct conditions and recovery attempts.
Keep your order information and clear photographs available when contacting support, as most suppliers assess grow kit issues based on images. If you purchased your kit from Kits de culture Mondo, our support team can review your photos and help determine the best next step.
Foire aux questions
Under good conditions, the first pins usually appear within about 7 to 14 days, depending on the strain and room temperature. Colder rooms and slower strains push this later, so a kit that has not pinned in the first week is normal.
For a fully colonised kit, the most common cause is temperature that is too low, followed by insufficient fresh air. Confirm the kit is at roughly 20 to 28 °C and getting controlled air exchange before trying anything else.
That is the classic sign of too much CO2 and not enough fresh air exchange. Give the kit more controlled airflow as described in your instructions, without letting it dry out.
Almost always no. White, fluffy or thread-like growth is healthy mycelium. Only coloured patches (blue, green, black or grey) or a bad smell indicate contamination.
No. Yellow to brown droplets are metabolites, sometimes called mushroom pee, and are harmless. They often signal the block is mature and ready to fruit.
A kit with established green or black mould cannot reliably be saved and should be disposed of, not reused. Prevention through clean handling and correct conditions is the best approach.
Only as described in your kit’s instructions. The supplied bag is designed to balance humidity and gas exchange; opening it too often or too long dries the surface and raises the contamination risk.
