Add whole wheat flour, water, dry yeast, salt, and sugar to a bowl and knead the dough.
Let the dough ferment for 1 hour (first rise).
Lightly knead the dough again and place it in a pan.
Let the dough ferment for 40 minutes (second rise).
Bake in a preheated oven at 180°C for 30 minutes, then let it cool.