How to Make Sweet Potato Fly

Updated June 20, 2017

Sweet potato fly is a fermented drink that could be a fun BIY project this autumn. If you're unfamiliar with fermented products like Kombucha or Kimchi, the taste might be different than you expect. Although the finished product may have traces of alcohol like Kombucha, it isn’t considered an alcoholic beverage because it may only contain traces of alcohol (unless you use it to make a bourbon cocktail). For the health nuts and fermenters out there, it’s a healthy, dairy-free alternative to eggnog or pumpkin spice lattes!

We adapted a recipe from Wild Fermentation by Sandor Ellix Katz:

Let's Get Wild!

We used a packet of dry yeast to keep it simple, but you could also use water kefir, whey liquid or Kombucha. Because we used a dry yeast, the first step was to activate it. Most yeast packets will have instructions on the back. For our process we heated ¼ water, added 1 tsp sugar, and the yeast packet in luke warm water - it’s important to note that any temperature above 110 degrees will kill the yeast, so using a thermometer to be sure it’s between 100 -110 is a pro-move. The yeast sits for 10 minutes while we prep the taters.

You can peel the potato skin or keep it for nutrients. Both potatoes should be fully grated, and should be rinsed with cold water prior to adding them to the stove.

On the stove, we add the ½ gallon of water, brown sugar and spices over medium heat. We changed regular sugar to brown sugar but either one is fine. Some recipes call for ½ cup of sugar, and some call for more than a cup - the more sugar you add, the sweeter the fly will be. We added seasonal spices to our recipe because ‘tis the season of Thanksgiving, you could also add molasses, opt for lemon or ginger, or not use spices at all! Katz’s recipe also has egg shell to balance the acidity level (which we chose not to use).

Once the water mixture reaches a low rolling boil, add the rinsed potatoes. Let the mixture sit at this temperature for a few minutes, then let it cool back to room temperature. Add the mixture and the activated yeast to a large jar and mix it up. Cover with an expandable top - we used a plastic bonnet that looks like a shower cap, but you could also use plastic wrap, a kitchen towel and rubber band, or other lid. It won’t bubble nearly as much as a beer so there is very little risk of bottle explosions here. Keep the jar out of sunlight at room temperature for 2-3 days, mixing it around a few times a day and visually checking the top to ensure no mold is growing. You’ll see that fermentation is happening as the mixture bubbles, foams, and separates.

After fermentation, strain the solids. We used a metal mesh strainer followed by a cheese cloth. At this point there will be about half the volume from the jar left. We used two 16 oz sanitized Kombucha jars to bottle the fly, and let it sit out for 12 more hours. We then put it in the refrigerator. Consume within one week - it will continue to ferment over that time, so the longer you wait the more fermented it will be! See our 3 minute video below.



Check out this DIY fermentation crock: