Maintaining an Italian Starter
Often when baking sweet breads, the benefits of the acidity produced by a sourdough starter are desirable, except for the sour flavor. The acidity contributes to aromas, extended shelf life and dough strength. Colomba Pasquale is a good example of this. In order to maintain a starter that fits in these parameters, you need to follow a feeding schedule that favors mild acid production and yeast activity.
The sourdough culture is maintained at a warm temperature (80 to 85°F) and fed every 4 hours. The more frequent feedings prevent the acetic acid from developing and the warmer temperatures favor lactic acid production. It is more common to maintain a starter at 100% hydration for mild acidity, but with the Italian starter, the hydration is 50%. The reason can be attributed more to tradition than theory. When there was no way to control the temperature of the room, the starter was fed every four hours and left at room temperature. Then, during the period that no one was in the bakery, the starter was wrapped tightly in a cloth and tied with a rope or string in a way that allowed minimual room for expansion.
Forcing the starter to mature in this enclosed space produced a mild flavor. For obvious reasons this method cannot be used with a liquid starter. If you are unable to control the temperature of the starter, this method is adequate. This style of starter is recommended for any sweet dough, such as the Colomba, Panettone and croissants.