Unless you're on a tight budget, I would bite the bullet and buy fresh
leaveners for important stuff that you probably don't want to be less
than perfect. Sure, there's some waste-not-want-not and/or tightwad
satisfaction to be had from using elderly ingredients, but is it worth
the risk? (Not that we're talking life and death here, to be sure...)

Bob
============================
In article >,
says...
> I apologize if this has been discussed before. I only recently joined
> this newsgroup.
>
> How does one tell whether their
> cream of tartar
> baking soda
> and baking powder
> are still fresh? Is there a test you can do? We're about to get ready
> to bake Christmas cookies, and I don't want things to come out flat if
> my ingredients aren't working properly.
>
> Thank you for any insight,
> Bobbett
>