1. Add water to the whole wheat flour, mix and soak for half an hour to 1 hour
2. Mix all ingredients, knead until expanded, add purple sweet potato pieces and knead well
3. Fermented in warm and humid places to 2-3 times, poke holes and do not rebound
4. Exhaust, round into the rattan basket. Continue to ferment in a warm and humid place to 2 times the size
5. Preheat the oven to 230 degrees, the middle and lower layer, 10 minutes, turn 200 degrees for about 30 minutes
6. carry out
