Keeping Food Cool In conversations and chatter about grid down situations, the subject of keeping food cool is often the topic of chatter. One can hear lots of different thoughts bouncing around and some folks talking about their personal steps. On hot summer days, an evening treat of a cool drink is priceless. It caps off a day of hard work. On a serious note, food that is not kept cool can become a serious health issue quickly. Lots of factors must be considered when devising your plan. Location, elevation, resources available, stationery vs transit, season of the year, what are you attempting to keep cool, security of the item you are trying to cool, number of people you are keeping hydrated ... You get the picture, right? The type of disaster may determine your environment and ability to cool food. The first step is to preserve the food you have available when the electricity goes out. What is in your refrigerator and freezer? These must be dealt with ASAP. Remember, the goal is to extend the life of the food item. So to the best of your ability, you want to extend the life of what is frozen. Personally, we can our frozen foods in order to prevent loss, period. This provides a convenience to us when we are ready to use it also. But the main reason we can is preserving the resources long term. But, what if it is to late? You haven't had time to can your items before the power goes out. Now what?
There's a few different methods you can use to attempt to keep your items cool. They are:
Water Tray/Wrap - Place food into waterproof container. Place in a tray of water, covered with a layer or two of flannel or burlap cloth. Keep the edges of the cloth in the tray to wick up water. This is a pretty basic plan to use and it does not require special equipment.
Terracotta Pot - For single items, such as beverages, place the container into a narrow terracotta pot that has no hole in the bottom (or has been plugged), and fill the pot with water. As the water seeps through the pot and evaporates, it will chill the water (and beverage) quite noticeably. Keep in a shady spot and maintain with water.
Food Bag - Place food into waterproof container/bags. Place container in several burlap/canvas bags/cloth. Wet the burlap sacks or canvas bag (shown), and suspend them from a tree branch or tripod (a breezy area will help). The evaporating water will cool the food, so make sure the bags stay wet and filled.
Zeer Pot - Terracotta pot within a pot, with a layer of wet sand between them. Place a towel or insulated lid over the top. Maintain the sand wet. Foodstuffs are placed in the center. I placed water in the inside of this one because water is a better conductor than air, but you can leave the water out of the interior if you need to store produce.
Note that all of the evaporative methods do not really work in the American "South"/Southeast, due to the high ambient humidity. These methods work optimally in drier, arid climates - where they can work really well.
Immersive Cooling - Place food items in waterproof containers (such as screw on lid plastic jars) and place containers into a mesh bag. Place bag into a running stream (spring-fed preferable) in a shady place, tied to a rock or tree. Note that this is really only advantageous if the water is much cooler than normal surface water, or is spring-fed. Dig down a little bit into the stream bed if necessary. Deeper areas of water will be cooler than shallow areas. If you can find an active spring, the temperature will likely be in the mid-50s, depending on spring size and terrain.
Well Cooling - A variant of immersive cooling is to secure your food containers in a bucket and lower down into a well. In olden days, food (especially milk and butter) was kept cool using this method. If you have a smaller diameter well (6"), then you can use a coffee can or small basket to make a bucket. Place foodstuffs inside a Ball canning jar, wrap with a cloth (since the bucket will be banging around a little on the way down), place that into your coffee can bucket, and lower down into the water several feet. Our well water is 59°F.
Short Term - If you needed to keep a vial of medicine cool, for example, you could activate a cold pack, and then tie/rubber band it around the vial. Place the combo into a wide-mouth insulated container, insulated lunch bag, or micro cooler.
Peltier Devices - Automobile beverage coolers, and similar devices, use a thermoelectric heat pump that transfers heat from one side of the device to the other. These can be used for heating or cooling. Most of these are 12V DC and can plug into the cigarette lighter in vehicles. These are not energy efficient compared to other means of cooling, but in pinch, or if you have an abundance of 12V power, this may be an option. Most of them will have a large heatsink and fan on the bottom or back. To get the most efficient cooling, you need to keep the airway free and flowing, as well as cool air supplied to keep the heatsink cool. This is another relative cooling situation; the more you can keep the heatsink cool, the cooler the inside will be. Typically, these devices will drop the temperature about 20° from the ambient temperature. Using additional modifications, such as better fans and/or water blocks used in computer overclocking, you can reach much lower temperature differences, including near and at freezing; again, this is not energy efficient. It is recommended you get a battery-saver that will automatically cut off power to the device if your battery starts getting low. This comes in handy so you don't drain your car battery overnight (like I have).
Ice Cubes - If ice cubes is all that is available (sometimes available in humanitarian efforts, but don't depend on it), you can place your foodstuffs into a cooler and pour the ice over them. If you have any airspace at the top left, fill it with newspaper or paper bags to help insulate. Place any solid frozen items (meat, soups, etc.) on the bottom of the cooler.
Ice Blocks/Jugs - In a cooler, place blocks of ice. Ice cubes or crushed ice will not last anywhere near as long as a block of ice. Use plastic shoeboxes in a deep-freezer to make blocks of ice, or fill plastic jugs about 2/3rds full (leave room for ice expansion). Once larger jugs start melting, the ice stays away from the sides, limiting the cooling effect. Direct ice method is best.
Pykrete/Icecrete - Mix sawdust/cellulose with the water (about 6:1) by weight you are going to freeze. Stir every now and then as it freezes so it will stay suspended. The sawdust helps the ice become self-insulated, and will last noticeably longer than a normal block of ice. Place block into a plastic bag to prevent making a mess as it melts. You could also make the same mix in plastic gallon jug containers to avoid the mess. Firsthand: I have made it in the past using
5-gallon buckets to fill voids in my deep freeze. They worked very well.
NOTE: Aside from true refrigerators and freezers, many of these methods only cool relative to the surrounding temperature. For example, many only give a 20° drop in temperature relative to the current temperature. Because of this, try to find ways to start with the lowest surrounding temperature. For example, using much colder well water to start with, or working in much more shaded environments. Also, find ways to pre-cool your items, especially foods. For example, placing a beverage container in cool water will help bring the temperature down faster, so that when you switch to another method it doesn't take longer just to get it down to a certain degree. Find ways to lighten the cooling load between methods.
Catering Thermoses/Thermal Container - Obtain large stainless-steel thermoses (about the size of a 5-gallon bucket) used by catering companies to transport and maintain hot or colds. These keep ice very well.
Cooler Selection -
Wrap the cooler in quilts/moving blankets and keep in the shade or cool place.
Try to find coolers similar to the extra-thick kind used by mail-order steaks or hospitals.
If you just need to keep/transport the perishables for several days without regularly accessing them, duct tape the cooler closed as well.
Remember, a good alternative to these options when saving meat during emergency situations is cooking and canning your beef, chicken, pork and other essentials. Doing this beforehand can save you a lot of time, stress, and money.
I hope this information helps you in some way.
Bravo Echo Out