Mushroom Cold Room & Growing Facility Guide
Engineering and operating guide for button-mushroom production and storage facilities in India.
Facility room types
A complete white-button mushroom unit has six functional rooms: (1) compost pasteurisation tunnel, (2) compost ageing, (3) spawn-run room, (4) cropping / fruiting room (multiple), (5) post-harvest cold room (0–2°C), (6) packaging hall. Small farmer units consolidate to 3 rooms; commercial units (5 MT/day) have 8–12 cropping chambers on staggered cycles.
Spawn run room (Phase III)
Conditions: 22–25°C air, 23–26°C compost, 95% RH, CO₂ 4000–5000 ppm (high CO₂ encouraged), dark. Duration 14–16 days. Refrigeration & humidification + fresh-air handling unit required. Bag rack spacing 30–40 cm for air flow. No light needed.
Cropping room (fruiting)
Conditions: air 16–18°C (flush 1), 14–16°C (flush 2–3), 85–90% RH, CO₂ <1000 ppm (high fresh-air exchange — 4–6 ACH), 50–100 lux light 12 hr/day. Each cropping room produces 3 flushes over 6–7 weeks, then turnaround (steam-clean + 24-hr cook-out at 65°C) before re-loading. Climate stability ±0.5°C is required for uniform pinning.
Post-harvest cold room
Pre-cooling within 2–4 hours of harvest to 0–2°C using a forced-air pre-cooler (NOT a regular cold room — pre-cooling is 8–10× faster). Storage at 0–2°C, 95% RH, 5–7 days. Use IQF or vacuum cooling for export-grade Grade A mushrooms.
Compost system
Pasteurisation tunnel: 58–60°C × 8 hr (pasteurisation), then 48–50°C × 4–6 days (conditioning for ammonia removal). Steam boiler 200–500 kg/hr. Aeration floor with reversing fan. Capacity: 10–25 tonnes per batch typically. A 5 MT/day mushroom unit needs a 60–80 tonne pasteurisation tunnel.
Typical BOQ (1 MT/day production)
Spawn-run room (40 m²): ₹6–8 lakh. Cropping chambers (4 × 60 m²): ₹28–36 lakh. Post-harvest cold room (15 m²): ₹3.5–4.5 lakh. Compost pasteurisation tunnel (15 MT): ₹12–16 lakh. HVAC (chiller, AHU, humidifier per room): ₹18–24 lakh. Steam boiler 200 kg/hr: ₹4.5–6 lakh. Controls (PLC, sensors, recipe): ₹6–8 lakh. Civil & MEP: ₹8–12 lakh. Total: ₹86 lakh – 1.15 crore + GST for a turnkey 1 MT/day unit.
Yield & economics
Indian benchmark: 18–22% biological efficiency (kg mushroom per kg dry compost). A 1 MT/day unit produces ~30 MT/month at ₹120–180/kg wholesale = ₹36–54 lakh/month revenue, ₹14–22 lakh/month margin after compost, labour, energy. Payback typically 2.5–4 years.
Frequently Asked Questions
What is the minimum viable mushroom unit size?
300 kg/day production with 2 cropping rooms is the practical minimum for commercial viability in India. Below this, fixed costs (boiler, control system) overwhelm margins.
Do I need a separate compost facility?
Many small/mid units buy ready Phase II compost from large producers and run only spawn-run + cropping. This eliminates the pasteurisation tunnel CAPEX (~₹14 lakh).
Need an engineered cold room quote?
Get a line-item BOQ from HyperCold's engineering team — heat load, PUF, refrigeration, controls, civil, all priced separately.
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