Enjoy this recipe from Made from Scratch.
Submitted by: Toni Smith
from Monroe, UT
4 gal. water
2-oz. bottle root beer concentrate
4 lbs. sugar
4 lbs. dry ice
Combine water, concentrate and sugar in a 5-gallon plastic container; stir with a plastic spoon until sugar is dissolved. Wearing heavy gloves, carefully add dry ice. Stir until ice is completely dissolved and stops bubbling. Root beer will stay cool and fizzy if refrigerated or kept on the countertop in an insulated airtight container. Makes 4 gallons.