@turquoise-- That's a good question. Although I don't know everything about this topic either, I think some breads are always fermented. For example, as far as I know, sourdough bread is always fermented.
The best way to make sure that your bread is fermented for a long time is actually to make it yourself at home. Combining the ingredients and yeast to form a dough and then leaving this at least overnight will result in a fermented bread.