"glad heart" > wrote:

> Is there any practical difference between sodium and potassium
> metabisulfite?

Sodium has received a bad reputation over the past few decades due to it's
(alleged) association with hypertension (high blood pressure). For this
reason, sodium metabisulphite is not permitted to be used by commercial
wineries in the US. I have read that sodium metabisulphite can impart a
bitter flavour to your wine, and for this reason I prefer potassium meta in
my wine. However, I still use the (less expensive) sodium meta for
sanitizing bottles and equipment, since the residual is rinsed or drained
off.

There is also a very small difference in the amount of SO2 (which is what we
really are trying to extract from these salts) per measured weight, but not
enough to be significant.