Heat 2 inches of oil in a heavy saucepan or fryer to 375 degrees. Grate the sweet potatoes into medium-sized bowl, cover them with boiling water, and let them stand for 15 minutes.
Drain off the water and slowly add the remaining ingredients, stirring to make sure that they are well mixed. You should have a thickish paste that will hold its shape when picked up in a tablespoon. If the mixture is too thick, add a bit of warm water. If it is too thin, add a bit more flour.
Drop the mixture, a few tablespoons at a time, into the hot oil and cook the fritters for 3 to 5 minutes, or until they float to the surface, turning them once to make sure that they are slightly browned on each side.