ULO controlled atmosphere storage, explained

ULO — Ultra Low Oxygen — is the gold standard for long-term apple storage. By dropping oxygen to around 1–2% and raising CO₂ inside a sealed cold room, we essentially put the fruit to sleep. Respiration slows, ripening pauses, and Brix and firmness are preserved for many months.

How it works

After harvest, apples are pre-cooled, then loaded into hermetically sealed ULO rooms held at roughly 1 °C. Nitrogen generators displace oxygen; CO₂ is regulated by lime scrubbers. Atmosphere is monitored continuously.

Why it matters for buyers

ULO is what makes a March-loaded Gala still snap when bitten. Without it, apples lose firmness within a few months. With it, we can offer Class I retail-grade fruit from September through August.

What we monitor

We track O₂, CO₂, ethylene, temperature and humidity in every room, with documented records available on request. Firmness and Brix are tested before every loading.

ULO vs. regular CA vs. cold storage

Regular cold storage holds apples 2–4 months. CA (controlled atmosphere) extends that to 6–8. ULO pushes shelf life to 10–11 months while preserving the eating quality the EU retail consumer expects.