The most efficient way to pack a cooler, according to science

Even though the Fourth of July is a popular time for eating, drinking, and socializing, every summer weekend has the potential to be legendary chill. However, all those positive feelings could disappear overnight due to one poorly packed cooler.

Even though it may be tempting to simply throw your sausages and cold drinks into an insulated box with some ice, a little preparation and the proper stacking technique will help your food and drink stay cold for a longer period of time. Additionally, you'll stop bacterial growth, which the Department of Agriculture claims happens quickly between 4 and 60 degrees Celsius (40 and 140 degrees Fahrenheit). And a weekend with infamously high bacterial counts will be one you remember for all the wrong reasons.

Anyone who has been to a summer party knows that guests are much more likely to graze on the drinks than the chilled food. The cook might be the only one to touch that. Storing sodas with steaks puts your meat at risk of spoiling much more quickly than it would in a designated portable meat locker because every time you open a cooler, warm air seeps in. Uncooked, room-temperature chicken is one thing, a warm Coke is quite another.

The ideal cooler for your trip is one you can fill to capacity with the least amount of empty space possible. You don't want priceless ice chilling unintentional air; instead, you want as much heat transfer as possible to take place between the ice and your goodies inside your cooler. Your primary concern will be size; choose one that can hold ice to at least two-thirds of its capacity, leaving the remaining space for food or beverages.

As a result of many major retailers' recommendations for a 2-to-1 ratio of ice to food or drink (such as Yeti and Canyon), we state that two-thirds of your cooler's contents should be ice. To visualize this, divide your cooler into thirds, and make sure your supplies fill one of the thirds. Just don't pack it that way; we'll talk about the proper packing strategy soon.

Beyond that, you are free to use any cooler. Naturally, newer coolers will incorporate the most recent insulation advancements, and if you're interested, our reviews team has offered their opinions on the best coolers of the year. Consider a white one as well, as it will likely absorb the least heat. But who are we to tell you to throw out the one you've had for years if you like it? We will mention that, as is customary, if you have two coolers with different levels of insulation, use the better one for food and the worse one for beverages.

It's best to make your own ice if you have enough notice. You won't have to worry about running out as long as you have water, and you can use the cold stuff in ways that you might not be able to if you buy a sack of ice from the store.

Naturally, not everyone has the time or motivation to start a commercial ice-making business in their home. Instead, look for the store that provides the coldest ice in your area. Yes, at 32 degrees (0 Celsius), water becomes a solid, but ice can become colder than that. More ice cubes will likely be produced in a commercial freezer than in your kitchen. One last thing about dry ice: we don't advise using it because it can be hazardous and isn't as easy to find. Wear gloves and place it at the bottom of the cooler so it won't likely contaminate any food or drink if you do manage to get your hands on some. If you do manage to get your hands on some, take all the necessary precautions.

You'll need some sort of insulator on top of this cold foundation, at the very least in your food cooler. Save some cardboard from the packaging you're throwing away; it's lightweight and has a reasonable level of heat resistance. You might even think about using a thin piece of wood, which won't get wet as easily and is a reasonably effective insulator. Use it if you have something better that is safe for food. Use your cooler to chill this material in advance for added cooling. In addition to providing a stable foundation and an additional barrier against heat penetration, this unmeltable layer will prevent food from falling into the freezing meltwater depths and becoming permanently spoiled.

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Consider which foods or beverages you'll want to access last and place those at the bottom. Uncooked meat is the main exception to this rule. If you don't have watertight containers, store it at the bottom of the container so that its juices won't contaminate other food. You should store it in watertight containers so that it won't leak everywhere. Another exception is delicate food; even if the hot dogs are going to be cooked last, avoid burying the buns in tons of ice and other materials. They'll be destroyed.

Try to layer everything as you go and pack ice into any empty spaces. Keep in mind what we said earlier: the longer everything stays cold, the less air there is in your cooler. Create a map of the contents of your portable icebox and organize everything inside it by category if you want to get really serious about cooler packing. You and your guests won't have to rummage around with the lid open as much if you know where everything is.

Once your cooler is fully loaded with food and ice, put something cold in the remaining space under the lid. Because these ice packs are flat and thin, we believe a reusable freezer sheet is the best option because it can easily double as a second lid. Reusable ice packs are a good backup option if you don't have any of those because they also frequently have a uniform flat surface and are larger than ice cubes (surface area is always important). Regular ice will also work, but it won't be as effective or last as long.

This summer, keep cool and may your beverages stay ice-cold.

The recommended ice-to-food ratio is one to two, and one-third of your cooler should be ice, according to a previous version of the story that was published on July 12, 2022. Actually, the proportion is 2-to-1, and ice should make up at least two-thirds of your cooler.