Use dry ice to keep things frozen; use frozen jell packs to keep things refrigerated and dry; and use regular ice to keep things refrigerated but wet.
Plan on using 10 to 20 pounds of dry ice for every 24-hour period depending upon the ice chest size. Dry ice will keep everything frozen in this ice chest, including extra ice, so consider keeping non-frozen goods refrigerated with regular ice in a separate ice chest. Dry ice sometimes comes in 10-inch squares, 2 inches thick, weighing about 10 pounds each square. Plan to put one square per 15 inches of ice chest length. This will work out to 2 squares (20 pounds) for an average 40-quart cooler. If you can only get pellets, separate them into 10-pound paper bags to spread them around and keep them from falling to the bottom. If you use plastic bags, make sure they are not sealed tight, or they will burst. For larger containers and longer camping or traveling times, multiply dry ice quantities by these rates. Dry Ice, at -109°F or -78°C, will freeze and keep frozen everything in its container until it is completely sublimated. These frozen items will take some extra time to thaw because they have been so cold.
HOW TO PACK DRY ICE
If the dry ice is placed on top of the food (cold sinks), it will work better. However, it is sometimes in the way so many people prefer to keep the dry ice on the bottom of the ice chest for convenience. When packing items in the container, fill all the space, if possible. Any “dead air space” will cause the dry ice to sublimate faster. The best storage container is a three-inch thick urethane insulated box. Lining the inside of your ice chest with sheets of Styrofoam will increase the life of dry ice. Dry ice sublimation (changing from a solid to a gas) will vary depending on the temperature, air pressure, and insulation thickness. The more dry ice you have stored in the container, the longer it will last.
TRANSPORTING BY AUTO OR VAN
Plan to pick up the dry ice as close to the time it is needed as possible. If possible, pack insulating items such as sleeping bags around the ice chest. This will stretch the time that the dry ice lasts. If it is transported inside a car or van (not in the trunk) for more than 10 minutes, ensure fresh air. After 15 minutes with dry ice only in its paper bag in the passenger seat next to me, I started to breathe faster and faster as though I were running a race. I couldn’t figure out why I was so out of breath until I saw the re-circulated position set, not fresh outside air. MAKE SURE FRESH AIR IS COMING IN – EVEN IN THE WINTER!
TRANSPORTING BY AIRPLANE
Pick up dry ice as close to departure time as convenient. Carry it in a well-insulated container such as an ice chest or insulated soft pack. If it is transported inside a car or van for more than 10 minutes, make sure there is fresh air available. Most airlines will allow you to carry no more than 2.5 kilograms (5.5 pounds) of dry ice on the airplane without special arrangements. Because dry ice will sublimate continuously from the time of purchase, you can confidently declare that there are no more than two kilograms when you check-in at the airport. Dry ice will sublimate slightly faster due to the lower pressure that the airline maintains during flight. Make plans to refrigerate or add dry ice when arriving at your destination.
PROTECT SPORT FISH AND GAME
Pack your trophy animal or fish in dry ice to minimize spoilage while transporting or shipping it home. Do not let the dry ice touch the game directly as it may cause superficial damage. Add dry ice to regular ice to extend its cooling. For best results, use an insulated container.
One time camping, my wife and I had too many leftovers to keep in our ice chest with ice. So we put the salad in our freezer ice chest. The dry ice was only 15 pounds at the beginning of the trip on the bottom of the ice chest, and extra ice was on top of it, and then the salad at the very top. We thought that the ice would be plenty of insulation, but we had a real crispy salad the next morning. A true ice lettuce salad!
HOW TO KEEP ICE FOR WEEKS
One camper reports: “I have a 100-quart Coleman that I pack before leaving with a 50-pound block of dry ice and two 25-pound blocks of regular ice on either side of the dry ice. The dry ice is wrapped in many layers of newspaper, which is a marvelous insulator. If the cooler is kept in the shade and covered with a heavy blanket, the dry ice will last from 8-10 days, at which time the wet ice first begins to melt. This will then last another 4-5 days. I would be willing to bet that using another method I heard (burying the ice chest in sand) in conjunction with mine would keep the wet ice available for 2-3 weeks. However, there is a downside. (1) Keep only frozen foods in the cooler until the dry ice is gone (no beer). (2) Lots of weight — the whole shebang weighs 100 lbs. sans food. Dry ice is very dense – a 50 lb. block is the same size as a 25 lb. block of wet ice.”
Jenifer Trout of Pittsburgh, Pennsylvania, reveals John Judson of the Quartercircle-Circle Ranch’s secret:
My family went with an outfitter on a horse packing trip in Colorado last summer. On the second night in the wilderness, John lamented that our menu was screwed up because the ice cream was “too frozen.” He pulled it out of the cooler and bounced it on a slab of wood. It was a brick! He’d brought the food in 2 small coolers, which doubled as stools. One was for refrigerated food, and the other was for frozen food. He’d move some food (mostly meat) from the frozen cooler to the refrigerated cooler each day. He used no wet ice or ice packs at all. We had ice cream on our third night out – after it had thawed to an appropriate temperature in the refrigerated cooler. His trick was a block of dry ice wrapped in newspaper – and it worked unbelievably well!