Island Answers
How Long Will Food Keep in a Sub-Zero During an Outage?
With the doors kept shut, FDA guidance gives the refrigerator side about four hours and a full freezer about 48, or 24 when half full. Past that, a thermometer decides. Once the power is steady, Driftwood Appliance Service, (206) 785-2960, can check a unit that will not pull down.
Why an empty cabinet warms faster
Sub-Zero’s own figure is shorter than the FDA’s because it describes an empty unit: the air typically rises above 45°F in the fresh-food side and 20°F in the freezer in about three hours. Packed food holds its cold far longer than air, which is why a full freezer outlasts a half-full one. Sub-Zero also suggests bags of ice to stretch the time.
Keep or throw out
The FDA says to discard refrigerated perishables held above 40°F for four hours or more, and that freezer food still carrying ice crystals, or at 40°F or below, may be refrozen. Sub-Zero draws its lines tighter: do not keep refrigerator food that warmed to 42°F, and do not refreeze freezer food that went above 20°F. Where the two disagree, follow the stricter one. Use an appliance thermometer, not the display, and never judge by smell or look.
- Written by
- Bjorn Aaltonen
- Trade
- Refrigeration technician, 15 yrs
- Holds
- EPA 608 certified
- Dated
