When the grid goes down, knowing how to keep your food cold becomes more than a convenience—it’s a survival necessity. Whether you're prepping for a long-term outage, living off-grid, or want to be prepared ahead of time, knowing how to keep your perishables cool without electricity is a must-have skill. Consider these options from MountainReady to help you stay one step ahead.
Why Cold Matters: The 40°F Rule
To prevent spoilage and bacterial growth, perishable foods like meat, dairy, and cooked leftovers must be stored at or below 40°F (4°C). Once temps rise above that, bacteria can multiply rapidly, making food unsafe to eat. The USDA recommends discarding perishable food if it has been above 40°F for more than 2 hours.
So how can you keep food cold without electricity? Here are 10 options to learn about right now:
1. Root Cellars: Nature’s Refrigerator
Before electricity, people relied on root cellars—underground storage spaces that stay cool year-round thanks to the earth’s natural insulation. Temperatures typically hover between 32°F and 40°F, which is a perfect temperature range for storing root veggies, apples, and even canned goods. If you don’t have a traditional cellar, you can also bury a trash can or cooler in a shaded area as a DIY alternative.
2. Zeer Pots: Clay-Powered Cooling
The Zeer pot, or pot-in-pot cooler, is an ancient method still used in arid regions today. It involves placing a smaller unglazed clay pot inside a larger unglazed one, filling the space between with sand. You then pour water over the sand. As the water evaporates, it pulls heat away from the inner pot, keeping contents cool. This method works best in dry climates where evaporation is more effective.
3. Ice Boxes: Old-School and Effective
Before modern refrigeration, ice boxes were the go-to for keeping food cold. You can recreate this by using a well-insulated cooler filled with ice or frozen gel packs. Adding salt to the ice can lower the melting point, keeping the contents colder for longer. Just keep in mind, the more you allow the cooler to stay closed, the longer it can retain the cold air.
4. Evaporative Cooling: Wet Cloth Method
Wrapping food in a damp cloth and placing it in a breezy, shaded area is another way you can provide temporary cooling through evaporation. This method isn't as effective in humid environments, but in dry climates, it can help keep food cool for short periods of time.
5. Frozen Bottles: DIY Cold Packs
Fill plastic bottles with water and freeze them ahead of time (you can also add salt). In a power outage, place these frozen bottles in your cooler or insulated container to keep food cold. As they melt, they’ll continue to absorb heat, extending the cooling period.
6. Saltwater Ice: A Colder Alternative
Mixing salt with water before freezing lowers the freezing point, creating ice that stays colder longer. These saltwater ice packs can be used in coolers to keep food at safe temperatures for extended periods.
7. Dry Ice: For Extended Cooling
If available, dry ice can keep food frozen for days. Handle with care, using gloves, and ensure proper ventilation, as dry ice releases carbon dioxide gas as it sublimates. Place it on top of the food in your cooler, as cold air sinks, to maximize efficiency.
8. Underground Storage: Dig a Hole
In a pinch, digging a hole in a shaded area and placing your food inside can provide temporary cooling. The deeper you go, the cooler the temperature, but even a shallow hole can offer some relief from the heat. Cover the hole with a board or tarp to keep out pests and debris.
9. Insulated Containers: Keep the Cold In
Using insulated containers or coolers can help maintain cold temperatures for your food. Line the container with reflective materials like aluminum foil to enhance insulation. Adding frozen gel packs or salted ice will extend the cooling period.
10. Amish Techniques: Traditional Wisdom
The Amish have long used non-electric methods to keep food cold, such as spring houses—small buildings built over a spring to utilize the naturally cold water for refrigeration. They also use ice houses, where large blocks of ice harvested in winter are stored in insulated buildings to last through the summer.
Final Tips
- Monitor Temperatures: Use a thermometer to ensure food stays below 40°F.
- Limit Opening: Keep coolers and containers closed as much as possible to retain cold air.
- Plan Ahead: Have a good understanding of your preferred backup methods and supplies ready before an outage occurs.
By incorporating these methods, you can keep your food safe and extend its shelf life during power outages or off-grid living. Stay prepared and stay safe!