My latest shopping spree on Amazon was for gel cold packs. I wanted some large ones that I could wrap around my knees. The ones I found were pricey and not quite big enough. So, after a bit of research online, I decided to make my own.
There are various ways to make cold packs: frozen bags of rice, peas, or ice cubes in water. The commercial kind I like is a flexible gel pack so that model was my goal.
I found a recipe using rubbing alcohol and water. Water freezes, alcohol does not, so mixing the two will produce a flexible ice pack. How flexible depends on the ratio of each. I tried 1/3 rubbing alcohol mixed with 2/3 water, double bagged in a large Ziploc bag. It froze stiff but became softer as it melted.
The method I like best uses regular liquid dish soap. I bought the cheapest I could find, $1 per bottle. Two large bottles were enough for a 2 gallon Ziploc bag, double bagged to prevent leakage. When frozen, it was more flexible than the alcohol/water mixture and seemed to melt at a slower pace, maintaining a flexible consistency longer.
Both of these methods produce a very cold pack, so I wrapped them in a pillow case to prevent frost nip. Hurrah, now I can freeze my knees with ease and our budget won’t feel the squeeze.