Make your own gel ice pack -- make any size you want, tuck it in any corner of the freezer . . . and you probably have the materials on hand!

Make Your Own Gel Ice Pack

An ice pack is a really handy thing on a boat.  There’s the obvious need in case of an injury, but also the less obvious use of keeping food cold.

Taking a cold dish to a pot luck where it might sit out for a while?  Having a sour cream dip on a day when it’s 95+ in the cockpit?  Putting it on ice would sure be nice!

If you’re like us, you may have a freezer, but not use it to make ice.  Those vertical ice cube trays just take up too much room in a tiny freezer . . . space I need for meat, fish and frozen yogurt!  I can spare a little space, but not enough for a whole tray.  So how to have an ice pack?

A homemade gel ice pack solves the problem.  By making it yourself, you can make any size pack you have space for in your freezer.  And since it doesn’t freeze solid, you can stick it in any corner or odd-shaped space in the freezer — even fold it or roll it up.  And when you take it out to use it, you can make it into pretty much whatever shape works best — wrap it around a neck or ankle, put it flat on your back, or cup it around a dish.

If you have a freezer aboard, you most likely have the other items you need to make your gel ice pack — and it will cost just a fraction of what those fancy ones in the drugstore cost!

You need:

2 Ziploc™ freezer bags — the type that press together are less likely to leak than the ones with the “zipper” and either quart or gallon size will work, depending on the size pack you want.

Good duct tape — lately we’ve been plagued with duct tape that is paper-thin and tears apart easily, so we’ve been using Gorilla Tape for jobs where the tape can’t fail — I highly recommend it but it’s not cheap.  (It’s available many places, such as Wal-mart and Home Depot).

1 part alcohol — rubbing alcohol or any rotgut stuff you’d use to stun a fish on the line (don’t use the good stuff!)

2 parts water — even sea water

Place one of the Ziplocs into a bowl or measuring cup so it stands upright (you could also have someone hold it upright), and pour the alcohol and water into it.  I used a quart Ziploc, 1/2 cup alcohol and 1 cup water.

Remove the bag from the container and carefully press it to get as much air out as possible, then press the sealing strips together.  It’s important to get as much air out as possible, as it makes it easier to fit into the freezer and to curve around an ankle or bowl once frozen.

Fold the top of the bag over just below the seal strip, and then duct tape the whole length of it, going slightly around the ends.

Label the other bag “Ice Pack” or something similar — you don’t want someone to try to eat it or throw it out.

Then put the taped bag in the second bag, get the air out, seal it and tape it.

Put it in the freezer any way it will fit — since it won’t freeze totally solid, but instead will be slushy, the shape just does not matter.

It took about 4 hours for my bag — with 1-1/2 cups of liquid total — to freeze to slush.

It may not look the prettiest, but putting a bowl with food that you need to keep cold while serving it inside another bowl with the gel ice pack in between works well.

Use it and re-use it . . . and if you suddenly need that extra bit of space in the freezer, you can take it out and put it in a locker, then put it back it the freezer when you have space.

Keep an eye out for wear on the outer bag.  If holes start to develop, either seal them with more duct tape, or replace the outer bag.  Don’t wait until there’s a hole in both bags and the “slush” leaks out!

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  • Kim - From Evenstar
    Posted at 09 August 2011 Reply

    Hi Carolyn – Just read the article you posted on the gel-pack (that we talked about in prior emails).

    BRAVO to you! What a great, interesting article. You do have the ‘gift’ of writing. The article was much more interesting than just listing the ingredients and how to build the gel-pack! And, using for food is a GREAT idea; As you can see, I have not been thinking ‘outside the box’

    Great article Carolyn!

    Will pass on any other tidbits I run across.

    Fair Winds!
    Kim 🙂

  • John Small Fridge
    Posted at 11 August 2011 Reply

    Hey what a great idea – I have bookmarked this page which is a bit unusual for me but I have not seen this described before. To be able to do it yourself certainly adds flexibility and the fact it doesn’t freeze hard is a big advantage for packing chilli-bins or for use with sports sprains or bruuising etc. The commercial freezer blocks being a defined shape can sometimes make things awkward so thanks for passing this on

  • Candy Ann Williams on Facebook
    Posted at 07 December 2011 Reply

    What another great tip!! Thanks.

  • MaryJo Boyle
    Posted at 08 December 2011 Reply

    Good information; thanks, Carolyn.

  • Sue Waudby on Facebook
    Posted at 22 January 2012 Reply

    Oh no I hope Dave is feeling better. Can’t wait to try this.

  • John
    Posted at 25 March 2012 Reply

    A volume of alcohol and water holds less “cold”(*) than an equal volume of water (above 32*), and much less than an equal volume of ice (below 32*).

    Indeed, gel cold packs which are most usually sold as “colder than ice” (because the “change of state” temp is about 25* compared to ice at 32*) will — for a given weight of gel pack vs ice — cool fewer cans of warm soda to nice drinking temp.

    (*) Sorry, a layman’s term inaccurate in the grand scheme of physics, but you get the idea.

    • Carolyn Shearlock
      Posted at 25 March 2012 Reply

      Yep, but for many of us who just don’t have room for ice cube tray, and a bag of water freezes into an weird and unusable shape, the gel pack works well. I like how it easily conforms to any shape you need it to!

  • Brytt
    Posted at 11 August 2013 Reply

    You are a lifesaver– thank you! I need to ship something I was afraid might melt and I have no time to order gel packs online and wait for them to arrive. Not only that, but these ingredients are all already in my kitchen. Wonderful! Thank you again

  • Darlene
    Posted at 30 January 2014 Reply

    What a great idea. If you use it to take something cold to a pot luck, you can always add a garnish around the ice pack to make it look pretty.

  • NegativeProfit(2squared)
    Posted at 10 May 2014 Reply

    Carolyn. If you you use the good “stuff” you could also have backup martinis or scotch on rocks. Lol

  • Kathe Spidell
    Posted at 06 August 2014 Reply

    Just made 2 of these for my 62 y.o.husband, who is getting his wisdom teeth taken out tomorrow. Hoping to make him as comfortable as possible.
    Thanks, from S/V Tribasa Cross!

  • Lupari Sue
    Posted at 02 March 2016 Reply

    Great idea. Now all we need to do is work on finding room for a freezer.

  • Joy C
    Posted at 02 March 2016 Reply

    Another idea — Food Safety. I use a flat sheet of gel ice to chill down leftovers before putting them into refrigeration. Shortens the time the hot food needs to cool down and keeps my refrigerator temperature more constant.

  • Richard Baxter
    Posted at 12 July 2017 Reply

    I use a water, salt, cornstarch concoction for my ice packs. Add a drop or 2 of food coloring & double bag in Vacuum Bags.
    Approx 4 part water, 1 part, salt, 1 part corstarch. Heat until thickened. Cool & Bag. Freeze.

    • The Boat Galley
      Posted at 13 July 2017 Reply

      I’m curious why the food coloring? And does it freeze hard or is it still pliable?

    • Richard Baxter
      Posted at 13 July 2017 Reply

      It is still pliable (adding enough salt is key).
      I have one pack that does not have quite enough salt that becomes solid, softens up quickly but still stays cold a long time.
      Food coloring is optional. I think the color was to denote its not edible. Mine are blues & purples.
      I found many recipes online. Used the salt version because I did not have alcohol.
      I would be curious to compare the two versions on how long they stay cold.

  • Martha Robinson
    Posted at 13 July 2017 Reply

    Great idea. I’ll put two of these together for cooling off in these hot summer months.

  • Tory Fine
    Posted at 13 July 2017 Reply

    This is the boatiest boat tip that ever boated. Like only a cruiser needs this and also this: “rubbing alcohol or any rotgut stuff you’d use to stun a fish on the line (don’t use the good stuff!)”

  • Jim Kindred
    Posted at 28 November 2017 Reply

    Thanks for the recipe Carolyn. We’ve used wet sponges in plastic bags which are hard and stiff… now I’m going to try adding your H2O/alcohol recipe with the sponges.

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