Mix flour and salt. Let yeast dissolve in a little water and fold in.
Add 1/2 to 3/4 liters of lukewarm water gradually. Stir the dough well and let rise in a warm place for 2 hours.
Knead in the acorn flour, work well! (The dough must be kneaded very firmly, otherwise it will fall apart!) Form an oblong loaf, place on floured baking sheet. Cut 4 times on top with floured kitchen knife. Let bread rise repeatedly.
Place in preheated hot oven , bake at medium heat for 60 to 80 min. Make a baking test: Poke a pointed stick into the bread! If dough sticks to the stick: continue baking! If the stick is dry: Bread is done!
(The baking time depends on the quality of the flour).