Water Balloon Ice Gems

    Kids, this is an easy way to make some decorations for your house if you live in a cold climate. You'll need water, balloons, food coloring, and outside temperatures below 25°F for at least two days. 

    Please note:  All chemicals and experiments can entail an element of risk, and no experiments should be performed without proper adult supervision.

    Step 1. Fill

    Open a balloon with one hand and drop 3-4 drops of food coloring into the dry balloon. Food coloring is affected by cold and may settle to one spot in your ice gem. Therefore there may not be a uniform color. Crystal clear gems are beautiful as well, so you don’t even have to add color. Secure the lip of the balloon over the lip of the kitchen or bathroom tap. Hold the lip of the balloon secure with one hand while you hold the weight of the balloon with the other hand. Fill the balloon with the coldest water you can get from the tap, and fill it slowly. Don’t overfill the balloon! Tie the balloon like you'd tie a normal water balloon. Don't worry if there's an air space at the top; it won't matter.

    Step 2. Freeze

    If it’s cold enough outside, that's the most convenient; otherwise, have an adult partner carve out enough space in a freezer. It’s wise to put something underneath the balloons. Though unlikely, the balloons might burst or stick to the ground or bottom of the freezer. Plastic grocery bags work fine. Make sure balloons rest on a flat surface, since you want the ice gems to have a flat bottom. Freeze for a day and then gently flip the balloons onto their side to continue freezing. They form ice toward the top of the balloon first, and flipping them onto their sides speeds up freezing the bottom half. Continue freezing for at least another day and night to ensure the core is completely frozen. After two days, check the balloon by gently shaking it back and forth. If you feel liquid sloshing around inside the gem, or see an air bubble moving around inside, put it back into the freezer or outside for another day.

    Step 3: Unwrap

    Now for the fun part! It's okay to unwrap your gems indoors, but make sure they're not in the warm air for too long. They start to melt fast, even with body heat. Take one at a time to a table with a regular-sized soup bowl. Gently remove the outer balloon coating, doing your best not to touch the surface of the gem (which instantly starts it melting.) The balloon and gem might have sharp, icy edges, so be careful. Each gem is different and unique. What will you find? After each one is unwrapped, use the bowl to transport the gem either into the freezer or outside. 


    Kathleen Carrado Gregar, PhD, Argonne National Labs 
    [email protected]
    March 2013


    Thanks to Milt Levenberg for sharing this idea.