Mix yeast in 1 cup warm water. Let stand for 5 mins. In very large pan, (I use my canning pan), mix sugar, water, and rootbeer extract. Stir until sugar is dissolved. Add yeast mixture and stir well. Using funnel, fill clean pop bottles leaving a 1 1/2 inch space at top. Cap using capper. Store on side for about 2 weeks in cool dark place, then stand upright. Chill before serving.
* Make sure you use regular soda pop bottles as the root beer as it works builds alot of pressure inside and could explode.