Time: 2 minutes
2 pounds dry ice
Find yourself some dry ice. You should plan to purchase within two hours of using it, as it won't last in your freezer much longer than that. It can be purchased at most large grocery stores. I just asked the checker for some, and one of the baggers went and grabbed it for me. It also helps if you ask for it to be wrapped in a paper sack, to keep it as cold as possible while you travel home. Keep in the freezer until you are ready to use it. Be careful not to touch it with your bare fingers, hands, arms or toes. It will give you an unwelcome burn. Drop the dried ice into a large pot, I opted to use my big canning pot. Pour the cold root beer over the ice. It will immediately start to bubble up and frothy puffs of Halloween wonder will come wafting out of your pot.If you have a hard time getting the smokey froth to come up from the bottom of the pot, try blowing on it a bit and then breaking up the dried ice with a knife. It should bubble and froth for you for about 10 minutes.