- 4 quarts cold water
- 2-3 cups granulated sugar (depending on how sweet you want it)
- 3 tablespoons root beer extract (see note)
- 1-2 pounds food-grade dry ice, broken into pieces (use the smaller amount if you want it to dissolve quickly and the greater amount if you want it to foam and bubble while serving)
- In a large pitcher stir together the water, sugar and root beer extract until the sugar is mostly dissolved. Take a little taste to see if you need more extract or sugar.
- In a well-ventilated area, carefully add the dry ice to the pitcher using insulated gloves or tongs and stir with a long-handled spoon so that the dry ice doesn’t stick to the bottom and sides of the container. The root beer will bubble and the dry ice fog will spill from the container (cool!).
- Continue stirring until it is mostly melted, 10-15 minutes.
- Ladle into cups, avoiding any large pieces of unmelted dry ice, and serve.
While dry ice is completely safe to drink once it is completely melted in the root beer, please keep in mind there are a few safety precautions to follow when working with it: use insulated gloves or tongs to transfer – never touch it directly as it can burn, add it to the root beer in a well-ventilated area so the carbon dioxide doesn’t build up and don’t let children (or adults) inhale the fog spilling from the pitcher, and be careful when breaking it up into pieces.
Because dry ice evaporates quickly and doesn’t store well, it’s best to buy only what you need and use it as soon as possible (store it in a styrofoam cooler if not using it right away as it is best not to keep it in every day freezers).