MAKES 4 LITERS

Complex and delicious, old-fashioned, home-brewed root beer has deep, intermingling notes of roots, bark, and spices, set against a background of molasses. Our formula is based on 19th-century recipes culled from The Saturday Evening Post, Scientific American, and Prairie Farmer, with guidance from Homemade Root Beer, Soda & Pop by Stephen Cresswell (Storey, 1998).

1⁄4 oz. dried sassafras root bark
1⁄4 oz. dried birch bark
1⁄4 oz. dried sarsaparilla root
1⁄8 oz. dried licorice root
1  1" piece fresh ginger, unpeeled
   and thinly sliced
1 vanilla bean, split
2 cups molasses
1⁄8 tsp. active dry yeast
 

1. Put sassafras root bark, birch bark, sarsaparilla root, licorice root, ginger, 1vanilla bean, and 2 qts. water into a medium pot and bring to a boil. Remove from heat, cover, and let steep for 2 hours.

2. Strain root-infused liquid through a cheesecloth-lined sieve into a plastic container that has been washed well with hot, soapy water. (Discard solids.) Add 2 qts. filtered water, stir well, and let cool to 75°.

3. Meanwhile, wash four 1-liter plastic soda bottles with hot, soapy water. Rinse well and air-dry. Stir molasses and dry yeast into the root-infused liquid; cover and set aside to let ferment for 15 minutes. Using a funnel, pour into bottles, filling to within 2" of top but no higher. Screw lids on tightly; set aside at room temperature to let ferment for 12 hours.

4. Chill for 2–5 days. The root beer's character will slowly change: after 2 days, it will taste strongly of molasses; at the end of 5 days the yeast will have eaten up more of the sugary molasses, creating a milder and slightly alcoholic beverage. When it's ready to drink, open bottles very slowly, easing the caps open little by little, to let any excess gas escape gradually. (Yeast produces a high level of natural carbonation that makes for a very fizzy drink.) Serve over ice.