Long fermentation is a fermentation that occurs over a long period of time. The longer the bread dough ferments, the better it tastes, allegedly. This happens due to the higher concentration of alcohol released by the yeast that consumed the sugar present in the dough. In sourdoughs, it results in a more sour bread, due to the higher concentration of acetic acid reseased by the bacteria present in the soughdough starter. Also, when the dough ferments for a long period of time, the gluten strains get more relaxed and easier to be worked, giving the final product an overall better consistency.