By Harold McGee
Although white flour is only about 1% fats, fat fragments, and phospholipids by weight, these substances are essential to the development of a well-raised bread. There’s evidence that some fatty materials can help stabilize the dough bubble walls as they expand and prevent premature rupture and collapse. Others become attached to starch granules and help soften the bread structure and slow staling. Similar ingredients added by the cook or manufacturer can magnify these useful effects.