After a power outage, what to keep and what to throw out
An outage asks two questions with different answers. The refrigerator is a question about hours. The freezer is a question about ice.
One note about the numbers below. The four-hour and 24-and-48-hour figures American kitchens use are federal guidance, and what the university extension services publish are restatements of it. Every figure here is quoted from the extension page that carries it, and that page is linked where the figure appears. The University of Minnesota's page names the original: the USDA Food Safety and Inspection Service's A Consumer's Guide to Food Safety: Severe Storms and Hurricanes.
Two clocks, and what they both assume
University of Illinois Extension gives the three numbers in their plainest form: refrigerated food is safe for up to 4 hours, food in a half-full freezer for up to 24 hours, and food in a full freezer for up to 48 (Illinois Extension, Power Outages).
Other services widen the refrigerator figure slightly, because a kitchen is not a fixed environment. Minnesota gives 4 to 6 hours "depending on the temperature of the kitchen" (UMN Extension, Power outages: keep food safe, reviewed 2021), and Clemson says refrigerated items should be safe as long as the power is out no more than about four to six hours (Clemson HGIC 3760, Food Safety in Power Outages). Plan against four and treat six as luck.
Every one of those numbers assumes a closed door. Minnesota's instruction is not to open the refrigerator at all except to add ice, and not to open the freezer unnecessarily. That is the practical reason to know what is in the freezer without looking, which is what a freezer inventory you will actually keep is for.
The refrigerator is judged by temperature, then by category
When the power comes back, the first reading is the thermometer, not the shelf. Clemson's rule is to discard any perishable food that has been above 40 °F for two hours or more. Illinois says the same from the other side: if the refrigerator reads above 40 °F and the power has been out four hours or longer, the perishable food goes.
Clemson's factsheet sorts the refrigerator by category, which is worth having, because the split is not intuitive. A selection from its two lists:
| Discard if above 40 °F for 2 hours or more | Safe at room temperature |
|---|---|
| Meat, poultry, fish, eggs and egg substitutes, raw or cooked | Butter or margarine |
| Milk, cream, yogurt and soft cheese | Hard and processed cheeses |
| Casseroles, stews and soups | Fresh fruits and vegetables |
| Lunch meats and hot dogs | Opened jars of vinegar-based salad dressing, jelly and relish |
| Fruit pies, bread, rolls and muffins |
Two things in that table catch people. Hard cheese survives and soft cheese does not, though most kitchens think of cheese as one food. And three condiments get a threshold of their own: Clemson says to discard open mayonnaise, tartar sauce and horseradish if they have been above 50 °F for more than eight hours, which is a longer leash than the milk gets and a shorter one than the jelly.
Cooked food sits in the left column with the raw meat it was made from. Why a cooked dish gets a short window even when it started out safe is covered in how long food really keeps.
The freezer is judged package by package
The freezer question is not how long the power was out. It is what state each package is in now.
The test is the same everywhere. Food that still contains ice crystals can be refrozen. Illinois states the threshold as ice crystals or 40 °F or colder. Penn State covers the case where the crystals are gone: food that has thawed completely but is still at or below 40 °F, confirmed with a digital thermometer, can also go back in (Penn State Extension, Keeping Food Safe When the Power Goes Out, March 2022). Minnesota names raw meat and poultry specifically as safe to refreeze at 40 °F or less.
What does not go back in, per Minnesota: meat and poultry that thawed through and warmed past 40 °F, cooked dishes, anything with an off color or odor, thawed vegetables, and melted ice cream. Clemson adds cream pies (Clemson HGIC 3780, Food Safety in Freezer Failure). Iowa State's list catches the awkward middle of most freezers — rice and pasta casseroles, and baked goods with a custard or cheese filling (Iowa State University Extension and Outreach, When the Home Freezer Stops, updated April 2025).
Refreezing costs quality even when it is safe. Iowa State says partial thawing and refreezing reduces quality, most noticeably in fruits and vegetables. Utah State suggests putting thawed fruit into cooking, or into jelly, jam and preserves, rather than expecting it back the way it went in (USU Extension, September 2020).
The decision is made one package at a time. Clemson says so without conditions: examine each package before deciding what to do with it, and discard it if the color or odor is poor or questionable. Iowa State reaches the package only when there is no appliance thermometer to read, but its discard list is unconditional, and it covers any food with questionable or poor color, odor or texture. One verdict for the whole cabinet will be wrong about part of it.
Nothing gets tasted
Minnesota, Penn State, both Clemson factsheets and Iowa State all say it in nearly the same words: food is not tasted to find out whether it is safe. Clemson gives the reason, which is that food can look and smell fine and still carry enough bacteria to make somebody ill. Iowa State puts the policy in six words: "When in doubt, throw it out."
It matters more after an outage than at any other time, because thawing and refreezing leaves nothing to see. A package that thawed for two days and then froze solid again looks exactly like the package beside it that never moved.
The outage nobody was home for
That is the hard case, and it has a cheap answer.
University of Nebraska-Lincoln Extension publishes a test that costs a plastic bag. Keep an ice cube or two in a sealed bag or small container in the freezer. Sealing it is the part that matters: UNL notes that an unsealed cube evaporates and disappears on its own, which leaves you with no reading at all. If the cube has melted out of its original shape, the power was off long enough to matter (UNL Food, How to Tell if Your Freezer Power Was Off When You Were Away, reviewed 2026).
Set it up before the trip rather than after it.
A full freezer buys the extra day
The whole difference between 24 hours and 48 is how much frozen mass is in the cabinet. Clemson puts the comparison in one sentence: a full freezer should keep food safe about two days, a half-full one about a day.
So filling the empty space is a real precaution rather than tidiness. Illinois's advice during an outage is to add bags of ice, ice packs or ice blocks to the refrigerator and freezer, and to move food into coolers with lids and ice for a long one. Water frozen in jugs ahead of time is the cheap version of an ice block: it holds temperature while it sits in the freezer, and it goes into the cooler when the food does.
Dry ice, with the caution attached
For a long outage, dry ice extends the freezer. The rate on Clemson's freezer-failure factsheet is 2½ to 3 pounds per cubic foot of freezer space, with more of it spread across the shelves in an upright model, handled with gloves or tongs because it burns skin (Clemson HGIC 3780, Food Safety in Freezer Failure).
Minnesota adds the warning that matters more than the quantity: ventilate the room, because carbon dioxide gas can accumulate and cause loss of consciousness or asphyxiation.
Estimates of how long a load lasts vary. Minnesota puts 50 pounds of dry ice at about four days in a full 20-cubic-foot freezer; Iowa State gives 50 pounds about two days in an 18-cubic-foot one. Take the poundage as the reliable part and the days as a range that depends on the cabinet, the insulation and the weather.
Write down what leaves
The last step happens with the trash bag already open, and it is the one that gets skipped.
List what you threw out. That list is what the restock gets planned from, and after a bad outage it is the only record that any of it existed. Whether a homeowner's or renter's policy pays for food lost in an outage is a question for that policy, but every version of the conversation starts with what was in the freezer.
So the inventory is worth being current before the storm rather than reconstructed after it. The thermometer and the clock decide what is safe. The list decides how much of the rest you get back.
Sources
- University of Illinois Extension, Power Outages
- University of Minnesota Extension, Power outages: keep food safe
- Penn State Extension, Keeping Food Safe When the Power Goes Out
- Clemson Cooperative Extension HGIC 3760, Food Safety in Power Outages
- Clemson Cooperative Extension HGIC 3780, Food Safety in Freezer Failure
- Iowa State University Extension and Outreach, When the Home Freezer Stops
- Utah State University Extension, Ask an Expert: What to Do When the Freezer Goes Out
- University of Nebraska-Lincoln Extension, How to Tell if Your Freezer Power Was Off When You Were Away
More guides
- A freezer inventory you will actually keep
- A pantry staples list, and how long each keeps
- Cooking from what you have
- Dented cans, rust, and when a can is not safe
- First in, first out, at home
- How long food really keeps
- How to store fruits and vegetables so they last
- What is safe in leftovers, and for how long
- Planning meals around what expires
- Spending less on groceries without coupons
- What a barcode tells you about your food
- What date labels on food actually mean
- What food waste costs a household
- What groceries cost per person
- When an AI says it can't tell
Keep track of it
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