I remember my parents making homemade root beer growing up, but have never made it myself....and it has been a long time since I have had it. One of our sons had a couple friends over the other night and we decided pizza and homemade root beer sounded good....and the root beer is fun. You need a 5 gallon insulated drink cooler to make this...or if you don't have one(like me), you can split the ingredients into two smaller ones.
Of course, being the terrible photographer that I am, I forgot to get a picture of the finished product. I only got this picture at the beginning. I almost didn't post because of that, but decided to share and next time we make it I will get some better pictures and update :)
Homemade Root Beer
4 lbs. sugar
3.5 gallons of water
1-2 2oz bottle of root beer concentrate (found in grocery stores by the vanilla), I added one bottle and ~1T.
4.5-5 lbs of dry ice
5 gallon insulated drink cooler
Directions: Combine sugar with one gallon of hot water and stir until the sugar has all dissolved. Add your root beer concentrate, start with the 2 ounce bottle....after you add all of your water, taste it and add a little extra concentrate...if you like a little stronger root beer taste. NOW, you want your root beer mixture to be as cold as possible before you add your dry ice, BUT you don't want to add the water then extra ice or you will water down your root beer. SO I put ice into the container that I was using to measure my water(2 qt pitcher), then filled it to the amount and added it to the warm sugar/root beer water. Add 2.5 gallons of water, so that you have the total of 3.5 gallons. If your root beer is cold when you add your dry ice, the dry ice will carbonate your root beer more...does that make sense? Add your dry ice and give everything a good stir. Put your lid on the container, loosely. If you put it on tight, the pressure will make it all explode. If you leave the lid completely off, your root beer will be flat. Brew your root beer for approx an hour. As it sits longer it will become slushy...yummy!! We left some overnight in our cooler and it was still slushy the next day.
Make sure that you handle the dry ice carefully and with gloves. If you touch it to bear skin, it will burn you. If you eat the slush, make sure that it is slush not the actual dry ice.
Also, I would recommend making this outside.
I hope this makes sense. If you have any questions, leave a comment and I'll try to answer.