A & W Root Beer Yield: 1 Servings 3/4 c sugar 3/4 c hot water 1 l cold seltzer water 1/2 t root beer concentrate 1/8 t root beer concentrate Dissolve the sugar in the hot water. Add the root beer concentrate and let cool. Combine the root beer mixture with the cold seltzer water, drink immediately or store in refrigerator in tightly covered container. Makes 5 cups.