How to Use an Ice Chest

1-gallon milk jugs work great for making your own block ice

1-gallon milk jugs work great for making your own block ice

It sounds simple; dump a bag of crushed ice into the ice chest, put in the food and drinks and then if you are really serious, layer another bag of crushed ice on top. This works fine if you are going on a picnic, but simply tossing a couple bags of crushed ice into the ice chest is completely inadequate for even short weekend camping trips.

The key to an ice chest is, of course, the ice. But the key to ice is mass, since an object with greater mass will hold its temperature longer than a similar object with less mass. For this reason a big block of solid ice, instead of hundreds of small cubes of ice, will last much longer, even if the block of ice and the bag of crushed ice are the same weight.

Even with block ice, it takes a lot of it to keep an ice chest cool for longer than 48 hours. I use 1-gallon milk jugs for making my own block ice. It is not only cheaper than buying block ice, but the jugs hold the melting water next to the ice, which helps slow down the melting process. It takes four milk jugs to keep one of the “5 day” or “6 day” ice chests cool for three or four days, at 80ºF.

There are some other steps that you can take in order to extend the life of the ice, and this involves pre-cooling of both the ice chest and anything that you plan to put into it. Pre-cooling is brining the inside temperature of the ice chest down to 40ºF before putting your ice inside. This keeps a warm ice chest from rapidly melting your ice until the ice can cool the inside of the ice chest. I use several frozen milk jugs to do this, but not the ones that I will use for the camping trip.

Warm food and drinks will also accelerate the melting of your ice, so it is important to pre-cool everything that you plan to put inside the ice chest. If you are camping for more than 3 days, it is a good idea to freeze food and perishable drinks, like milk, that you do not plan to use until later in the trip.

That is my system, but I am fortunate enough to have enough extra freezer space for 6 milk jugs of frozen water. How do you keep your ice chest going for the entire camping trip?

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31 thoughts on “How to Use an Ice Chest

  1. I freeze my water bottles and other “NON-carbonated” drinks before throwing them in the ice chest. You can use plastic, glass, or cans as long as it’s not carbonated. The key to getting them at different volumes is to buy them a week early. When I’m thirsty, I pour some into a glass, put the lid back on tight and toss the remainder in the freezer. When ready to pack the ice chest, I top off the partially full beverages using a couple of the full ones I still have in the fridge. Some people don’t want to go through all this effort; you can just freeze some and thaw them as needed but keep in mind, it can take several hours to thaw a fully frozen 16 oz bottle of water on an 80(F) degree day.

    I love this method because the frozen drinks can be layered in between other items, it eliminates the need to drain the cooler and prevents wet, soggy situations on short trips. For longer trips, adding cubed ice will increase the effectiveness of the cooler by 2-4 days depending on the cooler and reduce the amount of waste and draining. Freezing beverages at different levels are also really nice for day trips and long hikes because you can throw a few in your backpack which provides cold beverages throughout the day as they thaw. The plastic beverage bottles that are full do expand and create a rounded bottom, stretching the plastic slightly. This has never caused a problem for me because I don’t care if they stand upright. You can remove a little bit of the beverage before freezing to prevent this from happening if preferred.

    I also freeze gravy and meats. A steak or burger patty that will be grilled in a few days will be thawed perfectly by the time you’re ready to put it on the grill. Put your meat in a ziplock with your favorite marinade and it will soak as it thaws. Any gravy can be easily removed from a ziplock bag after freezing and heated in a saucepan over the fire for a quick and easy buscuits and gravy breakfast.

    P.S. I don’t like to freeze veggies and fruit because they become soggy after thawed.

    For those advising Roy he is wrong about the mass being a factor of cubed ice melting faster than a large block of ice – you are incorrect.

    You are correct when stating that the greater surface area ratio causes it to melt faster but there are two more factors you are missing. When you buy a bag of cubed ice it may weigh the same as the block in total, but you have to take into account that each cube of ice (which is really just a tiny block of ice) must be compared separately and is significantly smaller than the large block. One reason we must compare each cube separately aside from surface area ratio is its density (density does matter). Pure water will melt ice faster than air that is at the same temperature because water is denser than ice but the air is not. Withal, a small ice cube will have a lower density than a large block of ice causing it to melt even faster once water accumulates. If you want to get really technical we can also consider pressure, but I don’t think that is relevant to this blog. In conclusion, all three factors (mass, surface area, and density) contribute to the reason why cubed ice melts faster than a large block of ice.

    Happy camping, day-tripping, and tailgating!!!

  2. My ice box went out I put like 3 jugs of ice in a big ice chest and 2 jugs of ice in a small ice chest how long will it last and will my diet cokes go flat

  3. So over the 4th we are going camping for 4 days. I had a bunch of leftover milk bags from when I was nursing I filled those with 6oz of water and laid them flat to freeze. There’s about 50 of them. Do you think these will keep my cooler colder longer then just ice cubes? Or should I make bigger ice blocks?

  4. When packing “eggs” – buy some HARD plastic egg holders. Ive seen them in 6 & 12 egg sizes. I prefer the 6 egg size best. the stack easily and keeps eggs nice & safe till you need them. Priced often under 2-3 bucks – last forever. I’ve seen them in most major outdoor type stores, even the local Walmart’s.
    the paper egg boxes, when they get wet – disintegrate all too easy and you end up with loose and or broken eggs. the foam boxes crush too easily.

    I have 4 Coleman 70 extremes that I use. I often fo out for 5-7 days at a time. I layer the pre-cooled Ice chests with Ice cubes. spread rock salt over that then use TWO 10 lb blocks of ice in each cooler. & use either various rubber maid containers or food in zip-lock bags to keep food dry. I also bought several square bottles of milk (gallon)(plastic) and use those for milk VS. regular gallon containers that stack better in chest. and other times use them for ICE blocks on shorter trips. I have some cheap solar blankets I put over the chests. Even in 80-90 weather, after 7 days I often have ICE left.
    Like many others I use one cooler strictly for beverages to keep the food ones from being opened often.

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  6. I will take each evening’s main course – ie chicken breasts with whatever marinade etc in a Ziplock freezer bag. I fil a bread pan about 1/3 way w/ water & let freeze. Place chicken in & top off with ice. I can pull the next day’s dinner to the top of the ice chest & have it nicely thawed for the next day.

    I have used frozen gallon jugs w/ water too – they take up SO much room though both in my freezer & in the cooler. Had on fall out of freezer on foot. A fellow camper who has access to industrial freezer is to fill layers of water w/ days food, let freeze, repeat w said he can go out a week w/ food for 6 people for a week that way…

    I just bought a 40qt cooler that I can plug into my car or electrical outlet… Going to give that a shot- but I’ll have my backup ice blocks.

  7. quick caveat: “But the key to ice is mass, since an object with greater mass will hold its temperature longer than a similar object with less mass. For this reason a big block of solid ice, instead of hundreds of small cubes of ice, will last much longer, even if the block of ice and the bag of crushed ice are the same weight.”

    The statement is wrong, because ice of equal weights will have the same mass. What they don’t have are the same surface area, which is what makes little ice cubes melt faster.

  8. I also use dry ice. I buy a 5 pound block 24 hours before packing and cool the cooler to -20 to -30. Then most of what I take is frozen . I find it can last a week at 80 degrees if I keep the cooler shaded. A problem on longer trips is finding block ice to add. It never lasts as well as the first time.

  9. A solar-powered peltier junction can also aid in keeping your cooler cool.

    • i find that after i load the cooler, i layer newspaper on top of the contents and that seems to keep cool longer. even though the paper gets wet, it is still an insulation barrier.

  10. Um, your article contains some inaccuracy about why crushed/smaller ice melts faster than ice in blocks. The reason it does so is the increased surface area of the ice relative to its mass. The mass of 10 pounds of ice is the same, regardless of if it is crushed or in a block.

    • revel8or – right, I was thinking density and used mass incorrectly, but surface area is definitely a lot better way of explaining it – thanks!

      • Please don’t say “um” before making a point. It is snarky and obnoxious, and I find that it is becoming an increasing habit of people who think they are so bleeping smart smart.

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  12. Melynda – Funny, I just did the same thing for a seafood party over the neighbors, a few weeks ago! I guess I’m just used to my drinks staying cold 🙂

  13. We spent the day in Yellowstone today (just south of where we live) and I took your advice and pre-cooled our little cooler. Probably wasn’t necessary for one day with food that wouldn’t spoil anyway, but I was inspired!

  14. Melynda – all of my water jugs get booted from the freezer at Christmas time! 🙂 It is extremely handy to always have ice on hand, though.

  15. Keeping jugs of ice in the freezer also means less electricity use at home. Of course, Christmas candy works just as well, as long as you keep your freezer/fridge full.

  16. That’s a good idea, Breat – I’ve used some of the big ziplocks before, in one of our smaller coolers that we use for road trips.

  17. I have had good luck with freezing ziplock bags filled with water (leave room for expansion, of course). They are easily worked in and among the food in the ice chest.

  18. Thanks Eric! 2 of my milk jugs got kicked-out of the freezer yesterday for Christmas Candy – sigh.

  19. Stupid me for not thinking of the block of ice thing.. I was always crushing my ice before, but your tips make a lot of sense to me.

    One more thing I’ve learned from your site Roy!


    Eric’s last blog post..Looking forward

  20. You bet – we have family that works for Umpqua Dairy and they bring us ice cream all the time. We don’t take ice cream camping with us, though – we make our own at the campsite!

  21. Two words: dry ice. Our method ensures that we still have actual frozen food 4-5 days into our trip. I guess one day I’ll have to write up how we put our cooler together…

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  23. Thanks – I’m just hoping that I don’t have to go out and buy a bigger freezer! I’m getting away with using all the room in our 2nd fridge now, but I can just picture a bit of conflict coming down the road – lol

  24. Roy, I do the same thing with milk jugs. When I do cross country trips and even into the back country of Wyoming, I always use at least 4 milk jugs with frozen ice for my perishables. My mom always kept the cardboard milk containers in a freezer for use later on also. Good ideas.