Spawn to Substrate Calculator
Determine the optimal spawn-to-substrate ratio for your mushroom growing project. This calculator helps you achieve faster colonization, maximize yields, and estimate biological efficiency based on species and substrate combinations.
Spawn to Substrate Calculator
Understanding Spawn Rates
The spawn-to-substrate ratio is crucial for successful mushroom cultivation. Higher spawn rates lead to faster colonization and reduced contamination risk, but also increase costs. Finding the optimal balance is key to efficient production.
General Guidelines
- 5-10% spawn rate: Economical but slow colonization (3-4 weeks)
- 10-20% spawn rate: Standard for most commercial operations (2-3 weeks)
- 20-30% spawn rate: Fast colonization, higher cost (1-2 weeks)
Factors Affecting Spawn Rate Selection
- Species: Fast-growing species like oysters can use lower rates
- Temperature: Cooler temperatures may benefit from higher spawn rates
- Contamination pressure: Higher rates help outcompete contaminants
- Timeline: Commercial operations often use higher rates for faster turnover
Calculating Biological Efficiency
Biological Efficiency (BE) = (Fresh mushroom weight / Dry substrate weight) × 100
A BE of 100% means you harvested 1 kg of fresh mushrooms from 1 kg of dry substrate. Oyster mushrooms commonly achieve 75-150% BE, while shiitake typically ranges from 50-100%.
Pro Tip
For beginners, we recommend starting with a 15-20% spawn rate. This provides a good balance between cost and contamination resistance while you develop your technique.