Inoculation & Colonisation: Key Stages for Mushroom Growing Success
Inoculation introduces spawn or liquid culture to substrate, while colonisation sees mycelium spread throughout. Master these sterile techniques for contamination-free blocks ready to fruit.
What is Inoculation?
Inoculation transfers live mycelium into sterile substrate. Clean technique prevents moulds and bacteria that destroy grows. Success rate jumps from 30% to 90%+ with proper methods.
Tools for Sterile Inoculation
Essential equipment includes a still air box (SAB) or laminar flow hood, 70% isopropyl alcohol spray, flame (propane torch or lighter), nitrile gloves, liquid cultures or grain spawn, and grow bags with filter patch.
Step-by-Step Inoculation Process
1. Prepare Workspace
Spray SAB interior with 70% alcohol, wipe dry, assemble tools inside box, and work quickly (15-20 minutes max).
2. Sterilise Tools
Flame sterilise scalpel/needle until red hot, cool, and flame sterilise again before each use.
3. Shake Liquid Culture
Vigorously shake syringe to distribute mycelium, remove cap, flame needle, and inject 5-10ml per 2kg bag through injection port.
4. Seal Immediately
Tape injection hole with micropore tape (if not using our installed self healing injection port), massage bag to distribute culture evenly, and label with strain, date, batch.
Ideal Colonisation Conditions
Incubation occurs at 20-26°C for 10-21 days until white mycelium covers 100%. Recovery phase is 24-28°C for 3-5 days with initial growth after lag. Full run happens at 22-25°C for 14-28 days when knots form on surface.
Mycelium Growth Stages
Lag Phase (Day 1-3): Mycelium adapts to substrate. Exponential Growth (Day 4-14): White threads spread rapidly. Maturation (Day 15+): Surface knots signal readiness. Full Colonisation: Ready for fruiting when 5% over-colonised.
Optimal Spawn Rates
Liquid Culture uses 5-10ml per kg substrate (fastest). Grain Spawn requires 10-20% by weight of substrate. Bulk Spawn needs 5% for experienced growers. Higher rates mean faster colonisation and less contamination risk.
Contamination Warning Signs
During Colonisation, yellow liquid indicates bacteria, green patches signal Trichoderma mould, black spots show cobweb or ink cap, and off smells mean anaerobic bacteria. Isolate and destroy contaminated bags immediately.
Troubleshooting Colonisation Issues
For slow growth, increase temp to 26°C or check spawn viability. Stalled growth needs repositioning of bag and gentle massage, possibly too much light or incorrect temperatures. Bacterial wet spot means discard entire bag.
Storage Before Fruiting
Fully colonised blocks store at 4-10°C for 1-3 months. Avoid light and ethylene (fruits/veggies), and check weekly for overlay (too thick mycelium).
Moving to Fruiting Conditions
Perfect timing is 2-5% surface knots visible. Cut X slits (5cm) in grow bag, move to 15-20°C fruiting room, maintain 85-95% humidity with indirect light, and provide fresh air exchange daily.
Ready to inoculate? Source clean liquid cultures and sterilised grow bags from artisanmushrooms.ie. 🍄
