Tips for making block ice to use in a cooler for food storage. It seems like such a simple thing to do, yet I've had so many disasters.

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Okay, we all know the basics of how to make ice — put water in a container and stick it in the freezer.  But ice block machine is a little different from making ice cubes and I’ve had some absolutely spectacular displays of things that can go wrong — so I thought I’d pass along what I’ve learned.

So why even make block ice?  If you use a cooler for food storage, block ice will last far longer than ice cubes.  And making your own has two advantages:  it costs less and you can make the size blocks that work best for you.  Sometimes, too, it can be hard to find block ice and so you have to make your own — that’s our problem.

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Plan Ahead

Depending on how large a block you need, it will take a day or more for it to freeze solid from water.  So you can’t decide to make a block just a couple of hours before you’re leaving!

Sizing Up the Blocks

The first step in making your own block ice is to figure out what size block(s) will work best for you.  Then see if you can find a container that size . . . and if it will fit in your freezer.

After going out and buying a container that would totally fill my cooler, for example, I discovered that it wouldn’t fit in my freezer. Time to go back to the store.

I now have a slightly smaller container that fits in the freezer and I add some cube ice around the sides so that the bottom of the cooler is totally filled.  But I still have to do a lot of rearranging my freezer (read: cramming things into nooks and crannies) to make enough space for that bin.

Using Milk Jugs

Lots of people suggest using milk jugs (or other plastic bottles) to make block ice, and they can work well — but you need to know three things:

The plastic will insulate the ice to a certain extent, so it will last even longer . . . but it won’t keep your food as cold as if it weren’t encased in plastic; and

The sides of the bottles will bow out as the water freezes and expands, and you need to take this into consideration when figuring how many bottles you need.  With the bowing, you’ll have air gaps between the bottles.

Just as with my large pan (see the story below), don’t fill the whole bottle with water and then let it freeze.  The expanding water will very possibly break the bottle.  Only fill it partway, let it freeze, then add more water, etc.

Freezing the Water

Well, my first mistake was filling my plastic bin with water in the kitchen sink, then trying to put it in the freezer.  It’s heavy, it sloshes, and it’s awkward.  With my first step, water sloshed down the front of my shirt.  The second step did in the front of my shorts.  Then, just as I was putting the bin in the freezer, the door starting closing on me; most of the remaining water went on the floor.

So I put the plastic bin on the shelf in the freezer and used a pitcher to fill it up . . . almost to the top of its 6″ height.

That was my second mistake.

I figured that as the water froze and expanded, it would all go upward.  I learned differently when I checked on it the next morning.

It seems that my plastic bin was no match for the force of the large block of ice . . . and cold water.  Apparently, long before it was all frozen, the expanding water and ice cracked the plastic.  And the water that wasn’t yet frozen gushed through those gaps . . . and formed a 1″ deep puddle of water on the bottom of the freezer . . . where I had other frozen food.  Of course, the water froze there, entombing numerous bags of frozen veggies and meat.  And the next morning found me having to defrost the freezer to get the resulting “ice sculpture” out and apart.  And then a trip to the store to get another bin.

Now I put the plastic bin in the freezer and add about 1/2″ of water at a time — wait about an hour for it to freeze, then add some more.  No more broken bins!

You may be able to avoid this problem by using a metal pan — but it can be hard to find a metal pan that’s as large as you’d like.

Making a Fast Block

If you need to make a block in a hurry, fill your container with ice cubes, then pour water over it — again, a little at a time.  But each layer will freeze in 30 minutes or less, and you’ll have a block in about 6 hours (or less, depending on how thick you want it).

I never thought that making ice could be so complicated . . .