Dry ice can help create a spooky effect at your next Halloween party, but if it isn't properly stored, it will dissipate into a fog before you actually need it to. Dry ice is the frozen form of carbon dioxide, which is why, instead of melting into a liquid when heated, it instead turns into a gas. Since it's so cold (an extra-frigid -109.3°Fm to be exact), it melts or actually, per the scientific term, sublimates into a gas rather quickly. Luckily, there are a couple tips to follow that will ensure your dry ice stays frozen until you need it to billow spooky fog long into the night.
Before Using, Store It in a Cooler
As a rough rule, five pounds of dry ice will turn from a solid to a gas in 24 hours. Your best bet is always to pick up the block of ice a few hours before your party so it's as frozen as possible when your party starts. Once you get it home, store it in a cooler. An insulated cooler will keep the air inside it very cold and slow down the time it takes for the ice to change into a gas. Just be sure to keep the cooler slightly ajar, as any dry ice that does turn into a gas can build pressure and cause the lid to pop off. Wrapping the outside of the dry ice block with a few layers of towels or newspaper is another way to help insulate it. Do this before placing it in a cooler and you've got double the insulation. Pack any empty space in the cooler with towels or newspapers and you've got triple the insulation.
Read more: 5 Mistakes to Avoid When Using Dry Ice
How to Make That Spooky Fog Last
Once you're ready to get that fog effect going, whether it's in a cauldron or a cocktail, you'll need liquid to make it happen. Put the ice in liquid and it will instantly begin to melt into a gas, creating that smoky effect. Warm water creates more fog but it will disappear faster, while cooler water will give you less fog but will last longer. To keep that fog flowing through the night, just keep adding dry ice to whatever vessel holding it.
Read more: 3 Pro Tips for Using Dry Ice On Halloween