Sweet Potato Fly

Howsabout a fizzy, slightly sweet soda that isn’t a sugar bomb? A sweet potato fly is a wild-fermented soda carbonated through yeast and lactic acid bacteria, which is present on the skins of sweet potatoes. It’s similar to kvass, another wild-fermented fizzy drink from Russia made with beets and/or bread.

Makes: 1


  • 1/2 gallon mason jar with lid (or 2 quart jars)
  • fine mesh strainer
  • funnel
  • clean plastic bottles with caps


  • 2 cups grated sweet potato
  • 2 quarts water
  • 1 cup sugar
  • grated ginger, turmeric, or other herbs or spices (optional)


  • Add grated sweet potato, sugar, any flavorings, and water to the mason jar, seal lid and shake until sugar dissolves. 
  • Unscrew the lid but leave it covering the jar, so no dust or dog hair can get in but any CO2 built up during the fermentation process can escape. Allow jar to ferment at room temperature for 5-7 days. 
    To prevent mold or yeast formation on the surface, give the contents of the jar a daily shake. Screw on the lid first, shake, and then unscrew the lid again.
  • Strain the solids out (save them to add to bread, savory pancakes, or brownies) and drink as is. 
  • (optional). For a drier, fizzier drink, pour the liquid into a plastic bottle. Leave about 2 inches of headspace. Seal tightly and allow to carbonate at room temperature for several more days. When the bottle feels rock solid, know it’s fully carbonated. Transfer to fridge to cool before drinking. When ready to drink, slowly open and enjoy!