Most bread recipes call for the addition of yeast to make the bread rise. Many types of bread can be made without the addition of yeast, as there are yeasts in the air that the bread dough can utilize in order to rise naturally. The simplest way to make bread rise naturally is to make a sponge that has captured natural yeast from the air. Sourdough starter is one such popular sponge for making bread.
6 How well the dough sponge will rise will depend on the natural yeast in the air, along with the temperature and humidity of the room. Always let the dough sponge come to room temperature before using it in bread recipes. This will allow the yeast to become active as it warms up.
Place the dough ball back into a bowl and set the bowl in a warm area of your kitchen. Cover the bowl with a damp dishcloth or towel.
Remove any hard crust that forms on the dough ball. Work another cup of flour into the dough and let the ball rest for 8 to 12 hours.