Here's what SD is NOT:
- SD bread is NOT bread that has gone bad, hence, the sourness.
- NOT all SD bread is sour. Its sourness or lack of it depends on the degree of fermentation.
- SD bread is NOT just one type of bread. A great many kinds of regular bread can be turned into SD bread by replacing commercial yeast with a sourdough starter. After 7 years of baking sourdough bread, I find it an adventure to turn normal commercial yeasted breads into a full sourdough.
- You don't find SD in commercial bakeries much, because, "time is money" to a business, and SD flavours are slowly coaxed through a slow fermentation process.