Sanitizing with K Meta for the first time

[GreginND]

Grapes contain potassium. If your grapes (red or white) have a high amount of acid to begin with you will see tartrates forming. You can find these wine diamonds in many red wines.

If you rely on natural yeasts, you risk having weaker yeast strains working that require more nutrients. Did you add any yeast nutrients during fermentation? Not enough nitrogen and other nutrients during fermentation is the main cause of a sulfury aroma. These sulfur compounds (not metabisulfites) can become more pronounced and difficult to remove during aging as they convert to mercaptans and sulfides.

 

[Vinoors]

We did not add any nutrients. We've always made wine by just crushing/pressing the grapes, and letting nature do all the work without adding anything.

I have noticed a rotten egg smell in prior years, but not to the same extent. I have felt like that its tended to mellow out with time, but your comment would indicate the opposite.