"jab" > wrote in message ...
>I have been lurking around this group for a few weeks now and then. I used to
>like baking until my mom finally made me clean up afterwards. Haven't really
>baked since and that was over 40 years ago.
>
> This question may have been around in the past when I wasn't lurking, but
> there is something I always wanted to know. Why is baking SODA sold in a BOX
> and baking POWDER sold in a CAN?
>
> JAB

My guess is that baking soda will not react with the change in ambient humidity.
Since baking powder carries its own reagents (acid) when moistened a chain
reaction can take place and ruin the leavening power of the mixture.

Dimitri