Homemade Dry Ice Recipe

Dry ice is the solid form of carbon dioxide. It's extremely cold and sublimates into carbon dioxide gas, so it's useful for a wide variety of projects. While it's almost certainly less expensive to get dry ice from a store, it's possible to make it yourself using a CO₂ fire extinguisher or pressurized carbon dioxide in a tank or cartridge. You can get carbon dioxide at several types of stores (sporting good stores and some cookware stores), or you can order it online.

Homemade Dry Ice Materials

• CO₂ fire extinguisher or carbon dioxide tank.
• Cloth bag
• Heavy-duty gloves.
• Duct tape (optional)

Carbon dioxide fire extinguishers are labeled as such. If a fire extinguisher doesn't specify "carbon dioxide" assume it contains something else and won't work for this project.

Make Dry Ice

All you have to do is release the pressure on the gas and collect the dry ice. The reason you use a cloth bag is that it will allow carbon dioxide gas to escape, leaving just the dry ice.

1. Put on the heavy-duty gloves. You don't want to get frostbite from the dry ice!
2. Place the nozzle for the fire extinguisher or the CO₂ tank inside the cloth bag.
3. Either clamp your gloved hand around the mouth of the bag or else tape the bag onto the nozzle. Keep your gloved hand clear of the nozzle.
4. Discharge the fire extinguisher or, if you are using a CO₂ canister, partially open the valve. Dry ice will immediately begin forming in the bag.
5. Turn off the fire extinguisher or close the valve.
6. Gently shake the bag to dislodge dry ice from the nozzle. You can remove the bag and use your dry ice.
7. Dry ice sublimates quickly, but you can extend how long it lasts by storing the bag in the freezer.

Safety Precautions

• Dry ice freezes skin on contact. Be particularly careful to keep your hand away from the mouth of the fire extinguisher or outlet of the CO₂ tank.
• Don't eat dry ice. If you use the dry ice to cool drinks, be careful not to get it in your mouth. Dry ice is not edible.
• Dry ice generates pressure as it sublimates. Don't store dry ice in a sealed container or it may burst.