One other comment, commercial wineries are not allowed to use Sodium
Bisulfite as a wine addative. The must use Potasium Bisulfite. The
difference is that we really do not need to add more Sodium to our diet.
Sodium Bisulfite is a little cheaper but when you are only using 1/4 tsp per
5 gallons that really is irrelevant. But you may want to keep the Sodium
Bisulfite around for sanitizing. They both work but it is cheaper.

Ray