- 1). Locate a metal bowl that will fit inside your cauldron. Do not use a glass bowl. The extreme cold produced by the dry ice will cause it to shatter. Heavy plastic is acceptable, but the cold may cause it to crack or warp.
- 2). Buy dry ice from a grocery store, ice cream shop or Halloween specialty store. A half pound of dry ice will last at least 30 minutes in a medium-sized cauldron. For a 3-hour party you will need at least 3 pounds of dry ice.
- 3). Keep extra dry ice in the freezer until ready to use. Dry ice typically does not keep for longer than 24 to 48 hours in a home freezer. You can lower the temperature of your freezer, but this may hurt your compressor.
- 4). Place the metal bowel in the bottom of the cauldron.
- 5). Fill the bowl at least halfway with water. More water equals thicker smoke, but it also means the dry ice will run out faster.
- 6). Place dry ice into the water. Wear kitchen gloves or use a washcloth when handling dry ice. Large chunks of dry ice last longer than several small chunks.
- 7). Cover the bowl with aluminum foil. Poke several holes in the foil. The holes will allow the smoke to exit the bowl and will also protect your guests from splashes and flying chunks of dry ice if the cauldron is tipped over.
- 8). Set the cauldron in a well-ventilated area. The "smoke" released from dry ice is carbon dioxide gas.
Source...