Imagine it is the morning after a thunderstorm caused the power to go out and you’re worried about the food in your refrigerator. No one opened it, so has the food been preserved during the night? I did some research and these are my findings.
An unopened fridge will keep food safe for up to 4 hours without power. During those 4 hours, the internal temperature of the refrigerator will rise to a level that allows bacteria to propagate rapidly. After 4 hours most foods may no longer be safe for consumption and need to be thrown out.
Power outages bring a multitude of issues and here are a few things we need to consider.
- How should you treat food in your refrigerator after a prolonged power outage?
- Is it best to throw everything away, or can some items be retained without affecting food safety?
- While some power outages cannot be predicted, you can prepare for these eventualities to protect your food supply.
How Long Will The Food Last?
When the power goes out, one of your primary concerns will be directed at preserving your food supply. How long your refrigerated food remains viable is determined by:
- The starting temperature of your fridge
- Whether or not it has been opened during the power outage
- Fridge size
- How full the fridge was before the power went out
Ideally, your fridge should be set to between 35 °F and 38 °F (or 1.7 °C and 3.3 °), and the colder it is, the more time you have before your food starts to spoil. Opening the fridge, even for a few seconds, will significantly decrease the amount of time your fridge will stay cool. A broken seal on a fridge will also cause the cold air to escape more readily, reducing the length of time the food inside is preserved. As part of your preparedness plan, I recommend checking the seal on your fridge doors every few years.
On average, however, the USDA predicts that 4 hours can elapse without power before the food inside a refrigerator should be discarded. The 4 hour timeline set by the USDA is based on the time it takes for the inside of the fridge to rise above 40 °F and how long food can stay at that temperature before it is unfit for human consumption.
Food is kept below 40 °F (4 °C) in your refrigerator to preserve it by preventing degradation from fungi and the growth of bacteria. Between the temperatures of 40 °F and 140 °F, bacteria grow unimpeded and double in number every 20 minutes. For this reason, in food safety, this is considered the “danger zone”, and many foods should not be kept at these temperatures for more than two hours.
What to Keep, What to Throw Out
Most refrigerated food that has been above 40 °F for more than two hours should be considered unsafe to eat and should be thrown away. The same fate should be given to food that has been above 90 °F for an hour.
These rules apply to all meats, fish, eggs, lunchmeats, pizza, opened cans, casseroles, stews, shredded and soft cheeses, milk-based products, baby formula, custards, and puddings.
A few items in your refrigerator may still be viable after being near room temperature for a few hours.
However, take each item in turn and evaluate its viability before eating it. Look for signs of growth, such as mold, and signs of changes in texture or color. Additionally, appreciate any foul odors emanating from a product. All of these are clear indicators that the food has spoiled while the power was out.
How To Prepare For Power Outages
If you live in an area that is often encountering power outages, there are several things you can do to prepare for these occasions. Through good planning, you can be assured of when the fridge is no longer cold enough to preserve food, you have a method to save the food and keep your family safe from spoiled products, no matter how long the power supply is off.
Here are 7 things you can do to be proactive and prepare for power outages:
1. Install a thermometer
As storage temperature is crucial to food safety practice, being able to get a readout of the temperature is always useful. Many thermometers, like this one found on Amazon, can be installed easily inside a refrigerator and have an external readout. This way, you can see how quickly the temperature rises after the power supply is lost.
A thermometer can also help track the health of your refrigerator over time, regardless of the power supply. That way, you can tell once it is nearing the end of its life and can no longer regulate heat well. Additionally, most thermometers can be set to raise the alarm when a certain temperature threshold is met. So, when your fridge gets warm enough for the food inside to no longer be safely stored, it will alert you.
This can be particularly useful if the power goes out at night, and you would be left unaware otherwise.
2. Have coolers on hand
Once your fridge has been without power for several hours, it may be time to transfer the food out of it into smaller cold storage containers. In such a circumstance, you will be protecting the especially temperature-sensitive foods, such as poultry and dairy products.
Take your foods and transfer them to coolers and use either ice, ice packs, or instant ice packs (they break and become cold), to give your foodstuffs a few additional hours of preservation.
3. Have a small freezer for ice
For most people, a small chest freezer, like this one, this will seem like an unnecessary expense but can be worth it if your area often experiences prolonged power outages. You wouldn’t want to be opening your main freezer to get bags of ice out of it and decreasing how long it will remain cold. Further, by having a supply of ice water, you can be sure you have some clean drinking water on hand if your water supply is also compromised.
4. Have plenty of non-perishables
While the power is out, it is best not to open the fridge to keep it cool for as long as possible. Of course, you may be hungry during this time. To make sure you and your family keep nourished, always have items in the pantry that can serve as sustenance in such circumstances.
Cereals, protein bars, and dried fruits are great examples of food that can be easily stored for emergency rations. In the same vein, it is also a good idea to have a charcoal or a propane grill available if you need to cook food during an extended outage. It can also be a way to make raw products that will otherwise expire in your fridge last longer by cooking them.
It’s also not a bad idea to have at least a couple of weeks of long term emergency food and water on hand in case of extended power outages. I recommend My Patriot Supply, they have the best prices, quality, and a really good selection to choose from.
5. Don’t keep your fridge overstocked
If you are concerned about losing the money invested in the food in your fridge, a simple answer would be not to overfill your fridge. That way, you will not suffer a significant financial loss if a power outage lasts long enough to spoil your food. For families, this may not be an option, but for some people, shopping every few days instead of a more extensive, more infrequent shop, is a solution.
6. Fill your fridge with ice
This is where number 2 on my list comes to fruition. If you know that a massive storm is coming through, or some maintenance is planned where a known power outage is occurring, it can be a good idea to fill your fridge with ice.
If you have a large fridge and this isn’t possible, consider packing ice around the highly perishable items, such as meat or milk. That way, these items will be kept cold longer, maybe long enough for the power to come back on.
7. Buy a generator
If you keep a fully stocked fridge and losing those contents would be catastrophic, consider purchasing a generator, like my favorite one found on Amazon. This is also recommended for those that live in areas where power outages are frequent. A generator will allow you to keep your fridge operational no matter how long the power is out. Be sure to follow all guidelines for using a generator safely.
Refrigerated foods have a small window of around 4 hours in a power outage before they become unfit for consumption. During that time, the internal temperature of the fridge will climb to above 40 °F, which results in the food entering the danger zone, where bacteria multiplies rapidly.
To avoid losing the food inside your fridge, there are several methods available to prepare for a power outage. They range from buy ice and coolers to having a generator on hand. Through careful preparation, you can minimize food loss during a power cut.
How Long Does A Freezer Stay Cold Without Power?
A freezer will hold a freezing temperature for up to 48 hours before it starts to thaw. Such a timeline is possible with a large, well-packed freezer. A freezer that is only half full would be expected to last up to 24 hours before it starts to thaw. A full day of preservation is only possible for a freezer with a starting temperature of around -4 °F (-20 °C), with good seals that wasn’t opened after the power was lost.
Can I Keep Food Outside?
When a winter storm is passing through, and you know the power is likely to go out, you may wonder if you can store food outside instead of your fridge. Outdoor temperatures can often be below freezing, keeping food well below the bacterial growth temperature.
While this may seem like a solution to a power outage, the USDA does not suggest this as a viable option. That’s because although the outside temperature may be below the danger zone, areas with sunlight can easily have fluctuating temperatures throughout the day.
Furthermore, be aware that keeping foods outside makes them prone to contamination from dirt, bugs, and foraging animals. At best, only use cold temperatures outside to preserve food in the short-term, away from direct sunlight, and store in impenetrable containers.
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