Brussels sprouts should be cooled below 5°C as soon as possible, especially if harvested under warm conditions. Storage life of Brussels sprouts is maximised at 0°C with >90%RH. Sprouts can remain in good condition for 3 to 5 weeks at 0−3°C. At 5°C and above storage life is ended by yellowing.
Brussels sprouts are sometimes packed in top-iced styrofoam cartons. If the ice melts this can increase rots and discolouration. Freezing at contact points can cause dark, water-soaked spots.