Joel Hollingsworth wrote:
Aluminum holds up better in acid than in alkali.
Ferrous alloys are the opposite: acid attacks them, base protects them.
Every alloy has its own range of pH at which is is relatively protected against corrosion. In case anyone's really curious, these are systematically recorded in documents called Pourbaix diagrams.
Lye can completely destroy an aluminum object, and by "destroy" I mean "transform into a damp white paste." Phosphoric acid can leach some aluminum away, but that's a special case: it's safe to use with every other food acid I'm aware of.