I use Potassium Metabisulfite to preserve or stabilize the wine. Sodium Metabisulfite addes sodium, and most persons don't need more sodium in their diet. Supposedly, the sodium salt can affect the flavor, though I have never noticed it. Sodium M is less expensive, but Potassium M contains more SO2, so is it slightly more effective based on quantity. You could use Sodium M as a sanitizer for a less expensive sanitizer. I don't, because I use Iodophor Sanitizer because I have asthma and just a whiff of sanitizing solution with metabisulfitescauses me difficulty in breathing. Plus Iodophor is so much easier to use and is effective in only 2 minutes. Edited by: dfwwino