Put 500 ml of cold water in a medium-sized saucepan. Cut the bread into small pieces and add to the water in the saucepan. Press in the bread a little so that everything is well moistened and slowly bring to the boil. Let the bread boil briefly, about 2 minutes, and add the milk. Bring to the boil again, simmer for another minute, stirring constantly. Be careful, it splatters! Now add the sugar and mix everything well. Mash the cooked bread a little if you like. Remove the soup from the stove and serve.
This bread soup was served every morning at our medieval festival that lasted several days.