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Dry Onions

Recommended

Conventional cooling

Dynamic Cooling

Pre-cooling

De-greening

Ripening

General Tips for Dry Onions

Storage temperatureRelative Humidity (RH)DurationPre-coolingSensitivity to ethyleneEthylene ProductionControlled Atmosphere
Storage temperature: -0,2° to 0,5° C
Relative Humidity (RH): 72%-76%
Duration: 8-10 months
Pre-cooling: Not required
Sensitivity to ethylene: Low
Ethylene Production: Very low
Controlled Atmosphere: Not recommended

Dynamic Surface Drying (Essential): Before long-term storage, onions must be thoroughly dried in specialized cold rooms equipped with ventilation ducts and air-control systems.

Dynamic Cooling: Monitors and regulates all critical storage parameters at multiple points throughout the chamber 24/7, extending storage life by 15%–20% beyond conventional systems.

IMPORTANT TIPS
  • Dynamic Cooling is essential for preserving onion quality during long-term storage.
  • Avoid prolonged high temperatures during the pre-storage drying phase.
  • Do not store onions that were exposed to excessive humidity during cultivation.
  • Controlled drying can be performed directly inside the cold room by adjusting ventilation and humidity levels.
  • Delay the temperature drop below 10°C at the start of storage to promote the formation of additional protective skins.
  • Maintain drying conditions at 18°–25°C and 40% RH during the first five days after loading the cold chamber.
  • Use low-humidity refrigeration systems.
  • Remove ethylene via specialized ventilation systems.
  • Maintain moderate CO₂ levels to prevent spoilage and preserve onion quality.
  • Ensure continuous air recirculation within the chamber using independent fans, operating 24 hours a day.

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