COLLEGE STATION — With hurricane season in full swing, knowing what to do with the contents of the fridge and freezer during a power outage could save time and prevent the consumption of unsafe food.
Matt Taylor, Ph.D., associate professor for the Department of Animal Science in the College of Agriculture and Life Sciences at Texas A&M University explains how to best assess food safety during power outages.
Keeping the fridge or freezer closed as much as possible will help retain the cold air, and as always, if in doubt, throw it out!
Keeping it cool
One should not repeatedly open the door to a fridge or freezer once power is lost, as that will allow cold air to escape quickly and negate any insulation of the food that might have otherwise been in place.
Food safety, in most cases, can be protected with good judgment and common sense.
Having a refrigerator with a display that indicates internal temperature once power is restored will help. One can judge whether food has been at or above 40°F for two hours or more based on when power was lost and how much time has elapsed before electricity was restored.
For instance, if power was lost at midnight, temperatures inside the home rose into the 80s or 90s, and power is restored 12 hours later, it’s likely that food should be discarded.
What should be thrown out immediately?
Anything fresh or perishable like meat, poultry, eggs, fish, fluid milk and even juice that has or is suspected to have been sitting above 40°F for more than two hours should be thrown out immediately, he said.
“If you open the fridge and can smell or see the evidence of food spoilage, immediately start disposing of those culprits of the smells, off-colors, odors, spoilage – pretty much anything minimally processed or fresh. Anything that achieves an ambient temperature of 68-72°F, should also likely be disposed of because it will have sat at above 40°F for more than the recommended two hours.”
How long before frozen foods go bad?
Depending on the freezer, how well insulated it is, how full it is, what is in it, and how warm it actually gets, the timeframe will vary.
As FoodSafety.gov states, if a freezer is left unattended for some time after a power outage and is opened and fresh meat, poultry, fish and even fluid milk are still visibly frozen – think ice crystals still evident or frozen to the touch – those items can be either re–frozen or brought to thaw for immediate cooking and serving,” Taylor said. “The same is true for a variety of other dairy and produce-derived foods, that if still showing evidence of remaining frozen, one can either refreeze them, or initiate thawing if they intend to prepare and consume them immediately.”
How long can a refrigerator be off?
Some of the same factors like how full the fridge is, outside air temperature, etc. are also influential when it comes to food safety. But, for certain, refrigerated foods will not last as long as frozen.
It’s best to discard refrigerated foods, especially fresh meat, poultry, eggs, milk, fish or produce, if they are stored at or above 40°F for two hours or more.
“While proper cooking of fresh meat, poultry, eggs and fish may render them microbiologically safe, there are organisms that may produce toxic compounds while they grow on the food, and some of these toxins are not inactivated by cooking. So even if the pathogenic microbes are not present on the food, the food may still be unsafe to consume,” he said.
If a refrigerator has some type of display that can indicate the internal temperature once power is restored, then one can judge whether food has likely been at 40°F or more for greater than two hours based on knowledge of when power was lost, and how much time has elapsed since electricity was restored.
What to look for
There are a number of pieces of evidence to evaluate for signs food has become unusable, he explained.
“Unfortunately, food that is microbiologically unsafe will not show obvious signs of its lack of safety. However, foods that have supported the growth of microorganisms, such as when power is lost to refrigerators or freezers for long time periods, will typically undergo various forms of microbiological spoilage.”
The signs of spoilage include discoloration of the food, development of strong, often displeasing, odors and smells, or evidence of excess gas production that can be seen when a package deforms due to the excess gas production. Other signs of spoilage include cheesy, fecal odors, texture breakdown or loss, or the production of acids by fermentation.
Any combination of these is possible, but for fresh meat, poultry, fish and eggs, one should sniff out strong odors of putrefaction that would indicate protein breakdown, discoloration of the meat like brown, gray colors and excess juices in the pad, he said.
Produce may discolor some, may show evidence of softening and may have some odors, though it depends on its packaging. Milk will potentially show gas production, separation into curds and whey fractions, and typically present strong odors. Hard cheeses, fermented sausages that are not shelf-stable, and heavily processed foods may not show great damage due to their processing and stabilization.
Frozen foods that still show some signs of freezing, ice crystals, hard texture and still retain refrigeration conditions may be refrozen, as may a host of other foods. This presumes that they have not gone above refrigeration temperatures for more than two hours.
How to prepare for power outages
Preparation includes checking availability of back-up generators, stocking up on non-perishable foods like canned and further processed foods. Additionally, having a bottle of bleach on hand that can be used to make a sanitizer for surfaces is good to keep food preparation areas sanitary.
Stock up on bottled water if a concern, and fill bathtubs with water before you anticipate an outage for the sake of drinking/cooking, but such water must be boiled or fully cooked before drinking/consuming,” Taylor said. “The U.S. Food and Drug Administration also has the recommendation to have a manual can opener so you can actually use all those cans of food.”
When the power returns
“After power comes back, this is the best time to check the status of your fridge and freezer foods. The FDA has a good rule of thumb, when in doubt, throw it out. Apply the 40°F for two hours or more rule,” said Taylor. “Make sure to confirm municipal water is safe to drink/cook/bathe with during/after the event.”
What to do in a flood
The quick answer? Discard it. If your refrigerator or freezer was submerged by floodwaters — even partially, food is unsafe to use and must be discarded. Do not eat any food that may have come in contact with floodwater.