light wheat-gluten bread
麸 centers on a specific food made from wheat gluten: a light, bread-like product. The meaning is narrow and concrete, referring to this particular edible item.
麸 combines 麦 (wheat) with 夫, which likely contributes the sound フ. The character was created to name a specific wheat-gluten food.
Wheat 麦 and a man 夫: imagine a man kneading wheat dough to make light, airy gluten bread.
For フ, picture the wheat-gluten bread puffing up in the oven with a soft 'foo' sound: foo -> フ.