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?
See also…
- Camp Cooking Strategy
- 10 Tips to Better Outdoor Cooking
- A Camp Breakfast Everyone will Remember
- Kids Have a Ball, Camping with Ice Cream
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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.
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
Great tip! This is an excellent way to take up space in your cooler and keep it colder. Great site you have!
TheGearHouse
http://www.thegearhouse.com
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…
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!
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
Eric’s last blog post..Looking forward
Thanks Eric! 2 of my milk jugs got kicked-out of the freezer yesterday for Christmas Candy – sigh.
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.
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.
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.
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.
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!
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
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!