Put the sassafras root bark, wintergreen leaf, and cinnamon, coriander, and allspice if using, in a large pot on the stove.
Add the filtered water.
Turn the heat on high and bring to a boil.
Reduce to medium low and simmer for about 15-20 minutes.
Strain through a fine, mesh strainer or cheesecloth to remove herbs.
While still warm, add the sugar, molasses, and vanilla and stir until dissolved.
Let cool until warm, but not hot.
Add the lime juice and then then ginger bug or other culture and stir well.
Transfer to grolsch style bottles or jars with tight fitting lids and allow to ferment for several days at room temperature.
Check after two days for carbonation. When desired carbonation is reached, transfer to refrigerator and store until use.
If desired, the following can be added to the original boil but they are not needed: 2 cloves, 1 Tablespoon licorice root, 1 Tablespoon grated ginger root, 1 Tablespoon hops flowers, 1 teaspoon of anise or fennel