First of all, you need to decide how it is that you are going to carbonate the root beer and how quickly you will drink it. Your answer to this will dictate the recipe you use. First I will describe the recipe that my father used to use. I don't know the exact amounts because I was still a bit too you to pay attention to the details the last time he did it and it has been over two decades since then. You will need containers that you can seal air tight. My dad used a number of glass bottles that probably held about a quart each and were sealed with bottles cap of the sort that are still used on glass soda bottles. He also had a hand operated machine to actually place the caps on them. You must also make sure that the bottles are clean and sterile before you fill them. The root beer itself is made with root beer extract. (My dad used Hires extract, but I was unable to find that in a quick search of the web. So, it may be that they are not making it anymore.) Sugar Yeast Water Mix yeast with warm water in small container and set aside for a few minutes. Mix water, extract, and sugar in large container. (It seems to me that this recipe made about two or three gallons). Stir until extract is thoroughly mixed and the sugar is completely dissolved. Add water and yeast mixture and stir it in completely. Pour mixture into bottles and seal them. Let bottles sit in a dark place at room temperature at least a week. Open and enjoy. Note, this is basically the way root beer was originally made. Real root beer is slightly fermented to produce the carbonation. However, if you do use this recipe, then you should make sure that you use up the root beer in a timely manner. There were a few occasions when my dad made root beer and then my parents did not realize that they had not drunk it all. On these occasions they had one or two bottles that fermented until sufficient pressure built up to blow the cap off the bottle. Needless to say this usually resulted in a very sticky mess. The other way to make root beer if you are going to drink it fairly quickly is to skip the yeast and sealing it bottles and just add dry ice to the vat. As the dry ice sublimes in the root beer it will carbonate it. However, since this mixture is not going to be under pressure, the carbonation tends to be significantly weaker than that of the fermented root beer. If you wanted to put the root beer under pressure during the carbonation process with dry ice, I would recommend sealing it something like a pressure cooker. This way you would have an emergency valve to prevent the pressure from building up to the point of explosion. I would not recommend using anything less because of the danger of building up dangerous level of pressure inside the container. Also use the pressure release on top of the cooker to let off the pressure before you open it. So, there are a couple of ways to make root beer for your self.