Thanks Steve. Are you talking about a LAB ferment? Did you use Cobalt Sulfate? I would be interested in your “exact” recipe. How long did you ferment it? This is the kind of approach I am looking for. Otherwise I was thinking of citric acid.

I can get Cobalt Sulfate or EDTA Cobalt (12,5%), but I try to avoid EDTA because is an artificial chelate like Glyphosat which probably means that it remains around for a long time because there are no microorganism evolved to break it down.