This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
Take of molasses three gallons, add to this ten gallons of boiling water. Let this stand for two hours, then pour into a barrel, and add: powdered or bruised sassafras bark, one-half pound; winter-green bark, one-half pound; sarsaparilla root, one-half pound; fresh yeast, one pint. Water sufficient to make thirty to thirty-five gallons. Let this ferment twelve hours, when it can be drawn off and bottled. Instead of using the barks, the root-beer essence may be used for flavoring. Another formula is: five ounces sassafras; three ounces wild cherry bark; four gallons of molasses; five ounces allspice; five ounces wintergreen bark; one to one and one-half ounces of hops, and the same quantity of coriander seed. Pour boiling water on these ingredients, and let them stand twenty-four hours; strain, then add one to two pints of yeast and enough water to make thirty gallons. The next day draw off and bottle.