CanIFreezeThis

    Power-outage food check

    A live countdown of the two published windows — 48 hours for a full freezer, 24 hours half-full, with the door kept closed — plus the three checks that decide what you can keep when the power returns.

    The countdown

    How much window is left?

    Approximate is fine — but the timer only helps if the door has stayed shut since then.

    How full was the freezer?
    Has the door been open?
    °F

    This one reading settles it: at 40 °F or below, the food can be kept.

      The numbers

      What the published figures actually say

      With the door closedHolds forSource
      Refrigerator4 hoursCDC · FDA
      Full freezer48 hoursCDC · FDA
      Half-full freezer24 hoursCDC · FDA

      An empty freezer is not a legal category in either agency’s guidance — there is no published figure for one. The physics is simply worse: a freezer full of frozen food is insulated by its own contents, and one nearly empty is mostly air that exchanges heat with the room. This tool uses the 24-hour figure for anything that is not full, and warns you that it is the optimistic end.

      When the power returns

      Three checks, in order

      1. Look for ice crystals. Food that still has ice crystals is still cold enough. So is food at 40 °F (4 °C) or below if you can measure it. Either one can be refrozen or cooked — the quality will be worse, the safety is not in question.
      2. Discard what has been warm. Anything fully thawed and above 40 °F for two hours or more should be thrown out rather than cooked. Cooking kills bacteria, not the toxins some of them have already produced — which is the whole reason a cold chain matters.
      3. Group the survivors and refreeze them together. Refreeze in meal-sized packages, and put them at the bottom and back of the freezer where it is coldest. Whatever you are unsure about, treat as one meal this week rather than a month of storage.

      Ice-crystal and 40 °F refreezing rules from CDC and FDA; the two-hour discard rule from Cooperative Extension (Clemson HGIC). For a specific food’s own storage and refreezing note, the food card is the place to look.

      Questions

      What people actually ask

      How long does food stay frozen in a power cut?

      The CDC and FDA both give the same figures: a closed refrigerator holds food safely for about 4 hours, a full freezer for about 48 hours, and a half-full freezer for about 24 hours. They are estimates of how long the appliance holds cold with the door shut — not a guarantee that everything inside is still solid at the end of them. The fuller the freezer, the longer it holds, because frozen mass insulates itself.

      Should I open the freezer to check?

      No, and this is the one instruction worth repeating. Every opening lets the cold air out and the warm room air in, and the published windows assume the door stayed closed. If you need to know, wait — or keep a thermometer inside the freezer where you can read it through the door. Opening it at hour five to check is how an hour-ten problem is created.

      Is it safe to refreeze food that thawed?

      If it still has ice crystals, or it is 40 °F (4 °C) or below, the CDC and FDA both say it can be refrozen or cooked. Quality will suffer — a refrozen steak weeps more when you cook it — but it is not a safety problem. If it has been above 40 °F for two hours or more, discard it rather than cooking with it.

      What about the food in the refrigerator, not the freezer?

      Four hours with the door closed is the working figure. After that, treat refrigerated perishables that spent four hours or more above 40 °F as unsafe and discard them. A refrigerator that has been opened repeatedly loses its cold far faster than four hours, so the number is worth less than your own thermometer reading.

      Where these numbers come from

      Sources

      Every figure this tool computes with is published guidance, cited here rather than summarized from memory. Where the published guidance is silent — a per-pound thawing rate for a cut nobody publishes one for, or how long a nearly empty freezer really holds — the tool says so and you get a check instead of an invented number.

      1. CDC — Keep Food Safe After an Emergency 4 hours for a closed refrigerator, 48 hours for a full freezer, 24 hours half-full, and what may be refrozen
      2. FDA — Food and Water Safety During Power Outages the same outage windows, and the 40 °F ice-crystal test for refreezing
      3. USDA FSIS — The Big Thaw refrigerator, cold-water and microwave thawing, and cooking from frozen
      4. USDA FSIS — Turkey Basics: Safe Thawing 24 hours per 4–5 lb in the refrigerator; 30 minutes per pound in cold water
      5. USDA FSIS — Freezing and Food Safety 0 °F, quality windows, and refreezing after a refrigerator thaw
      6. USDA FoodKeeper App the storage windows behind every food page on this site

      Planning figures from public guidance, not a test of your particular package — for that, the food is the instrument. Read our editorial policy and the freezer safety standard.