Stormin Mormon wrote, on Wed, 14 Jan 2015 09:11:28 -0500:

> By the time you endure the expense of the ingredients,
> you'd have been better tt go buy baking powder at your
> grocery.

Baking powder, at the store, is about $6 per pound.

Baking soda, alone, is five cents a pound.
Cream of tartar is seven dollars a pound.
Corn starch, if used, is two dollars a pound.

So, it would seem that the entire expense of the baking
powder is in the cream of tartar.

Because of that, one would expect grocery store suppliers
to skimp on that particular ingredient, substituting
something cheaper instead.

Do they?