We recently visited a working commercial mushroom farm. They are producing functional mushrooms like Lion's Mane. As impressive as it was, one thing stood out to us: they operate with a 70% contamination rate. Surprisingly, this isn’t unusual. At Mentis, we do much better, with our grow bags typically failing 10-15% of the time. Nonetheless, our key takeaway was that growing mushrooms is hard. Really hard!

Contamination is the arch-nemesis of any mushroom grower. It is hands down the biggest cause of failure. Take a look at our instructions on how to identify contamination here. Of course, many other things can go wrong too.

The Mentis Toolbox is designed to simplify the process of growing mushrooms. However, it still isn’t perfect. In this blog post, we’ll cover the 5 most common issues and how they can be easily resolved.

 

Nothing seems to be happening. Colonisation hasn’t started.

This is a common concern for new growers. The first step is to remain patient. Colonisation can take time, usually 3-4 weeks, before visible signs of growth appear. However, if nothing has happened after four weeks, it’s possible that the spores you injected were not viable, or that the moisture content in the grow bag wasn’t evenly distributed.

Solution: Give the grow bag a gentle but thorough massage to mix the contents evenly. Ensure the bag is kept at the right temperature. We recommend incubating at 24°C or 28-32°C using the Thermal Sleeve. Depending on the ambient temperature where your Toolbox is stored, there can be a temperature loss of 4-8°C between the Thermal Sleeve setting and the incubation temperature of the grow bag. If, after 4-6 weeks from injection, the contents of the grow bag look exactly the same as when received, consider starting again with fresh spores. If you've had success with the same spore syringe before, please contact us at hello@getmentis.com.

Colonisation has started but doesn’t seem to be continuing.

Stalled colonisation can occur when environmental conditions aren’t ideal, even after a successful start. Factors like temperature, moisture, and airflow can all play a role.

Solution: Increase the temperature of the Thermal Sleeve by two degrees, but avoid going above 32°C. Gently break up the existing mycelium and redistribute it within the grow bag. This should encourage further growth.

Colonisation has finished. The mycelial cake has fully formed, i.e., it is completely white. However, fruiting is not happening.

Once the mycelium has fully colonised the substrate, fruiting should begin soon after. If it doesn’t, this could be due to a lack of proper environmental triggers.

Solution: With Mentis grow bags, for simplicity, you shouldn’t need to reduce the Thermal Sleeve temperature to induce fruiting. However, mushrooms typically prefer slightly cooler temperatures for fruiting. Try lowering the Thermal Sleeve by 2-4°C, setting it to 26-28°C. Increase humidity by cutting open the top of the bag and misting daily (15-20 sprays). Ensure there’s plenty of indirect light, as mushrooms need light to trigger fruiting. If fruiting still hasn’t occurred after two weeks, perform the Soak Step: https://getmentis.com/pages/the-soak-step.

Fruiting is happening, but my mushrooms have long thin stems.

Thin, leggy mushrooms usually indicate insufficient light or too much CO2 buildup, meaning the mushrooms aren’t getting enough oxygen.

Solution: Move the grow bag to a location with more indirect light, or use a grow light if needed. Ensure there’s adequate airflow by opening the bag daily. This will allow for gas exchange and help the mushrooms develop thicker, healthier stems.

Fruiting is happening, but my mushrooms are drying out.

Drying mushrooms typically mean that the humidity is too low. Mushrooms need a high-humidity environment to grow properly.

Solution: Start misting the inside of the bag. Spray the sides of the walls 15-20 times daily.

We hope this article is helpful. Of course, feel free to reach out to us for support if you have any questions. We’re here to help you!

Happy growing, and thanks for reading The Mushroom Farmer.