Many lacto-fermented sweet potato recipes are made with cooked and mashed sweet potatoes. This recipe is for raw sweet potatoes. It calls for leaving the skin intact. The result will be pretty crunchy, like carrots, but quite digestible, due to the fermentation.
5 pounds sweet potatoes, with any surface dirt rinsed off, sliced very thinly
In a large bowl combine sweet potato slices with ginger, onion, and cayenne powder. Sprinkle with salt to taste.
Pound the sweet potatoes a bit with a Cabbage Crusher or potato masher to encourage the release of the juices and to help the brine develop faster.
Once the brine begins to form, transfer to a fermentation vessel and weigh down with weights. Push down with a clean hand, if necessary, until the brine goes above the vegetables.
Cover and ferment 5-10 days. It is important to keep this ferment in a cool place (under 65°F) as a quick fermentation could result in a large amount of alcohol being produced.
If you are not using an airlock, be sure to burp the jars regularly to release pressure.
Once the potatoes are pleasantly fermented, move them to cold storage. If the fermenting environment has become warmer, move the potatoes to cold storage after 2-3 days, and leave them to ferment for another 1-2 weeks.