The older machines did come with cast aluminum alloy beaters and dough
hooks (and some pretty crummy plated steel mixing bowls which got really
nasty when the plating wore off). The epoxy coated beaters and SS bowls
came relatively recently in the KitchenAid lineage.

I've seen the effect the OP described, with bread dough, and assumed it
was oxidation rubbing off. But I don't know what can be done to prevent
it. I would try washing off the beater with something mild and gently
abrasive like Bon Ami or maybe baking soda just prior to use to see if
that helped.

But I would also look into replacing the beaters with newer, coated
ones, if only because of the persistent negative buzz about the effects
of execssive intake of aluminum compounds. There's probably a reason
why KitchenAid started coating their beaters, beyond the "attractive
gray swirl effect" the old ones sometimes produced...

Bob
==========================
In article >,
says...
> wrote:
> > Does anyone elses kitchenaid mixer paddle leave gray stains on the
> > food? It's particularly obvious on cheesecake, with gray swirly
> > markings on the finished product. Have seen when mixing cornbread also.
> >
> > Any ideas?
> >
>
>
> Are they cast aluminum? All the attachments for my Kitchenaid (except
> the whisk) are made of steel coated with some kind of tough plastic --
> almost like enamel but tougher and not as hard. I bought it almost 20
> years ago. What you are describing sounds like aluminum.
>
> Bob
>