Why do bakers say to put butter over beer bread?

Bakers don't typically say to put butter over beer bread. You're likely thinking of cornbread. The reason butter is often added to cornbread is because it:

* Adds moisture and richness: Butter is a fat, and fats help to make baked goods moist and flavorful.

* Enhances the flavor: The buttery flavor complements the sweetness of the cornmeal.

* Improves texture: Butter can help create a softer, more tender crumb.

While butter is often used with cornbread, you can certainly use it with beer bread too. It will add similar benefits as described above, making the bread more flavorful and moist. However, beer bread often has a more dense and hearty texture, so the butter might not be as necessary for softness.

It's important to note that there are different variations of both cornbread and beer bread recipes, so some may call for butter and others may not. Ultimately, it comes down to personal preference.