Part of the doughnut essence contains ammonium bicarbonate. Crispy outside and fluffy inside big doughnut recipe: 9.5 pounds of gluten flour, 0.5 pounds of eggs, 50-100 grams of noodles Xin pastry, 50 grams of food-grade ammonium carbonate, 20-60 grams of sugar, 70-100 grams of salt, 30 degrees of water 5.8 pounds. Process: Flour, noodle Xin pastry dry mix well. Add the egg, ammonium carbonate, sugar, salt into the water to melt, add the flour and make a dough, do not knead. Cover the dough with a damp cloth, let it rise for 10 minutes, knead and punch it once, let it rise again for 10 minutes, knead and punch it again, knead it into a strip, wrap it with plastic wrap and let it ferment at low temperature for 6-8 hours. Take out the molding, put into the 200 degrees frying pan deep-fried, to keep turning, deep-fried until crispy.