I have been baking muffins recently. I opened a can of baking
powder, which was not past its expiration date or even close to
it. I realized last night that it must, nonetheless, be old,
because the muffins just are not rising much. Sooo, I am wondering:

1) Does BP age in an unopened can? I note that the cans are not
all metal now, so I imagine the cardboard would not offer the same
level of protection.

2. Do all double-acting BPs have the same leavening power? The
one I have open is Rumford, but I have always used Calumet in the
past. For some odd reason, Calumet is almost impossible to find
here now.

Thanks,


--
Jean B.