H2s odor still lingering 18

buttuming for a minute that the problem is solely H2S, then Rick is likely faced with H2S that has already progressed to mercaptans or worse. buttuming that is 'simply' H2S, he can try to remedy with copper sulfate - but needs to be very careful; this is deadly stuff. To treat a small quanbreasty like that, he will need to measurements of grains - not grams. The Margolit book is the best guide.

I had a similar problem this last year with some Syrah. I had about 20+ gallons in 4 large carboys (6.5's and one 5) The H2S did not become apparent until a week or so into secondary. Because it appeared in all but one carboy, I am still perplexed as to cause (if it was in primary - why wouldn't it show in all 4 carboys? If in secondary, why in three out of 4? hmmm). anyway, tried a splashy racking, which reduced it, but didn;t solve it. I then spent a couple weeks learning about copper sulfate and then trying it. Too late. I ended dumping all but the one carboy. I now have 5 gallons of wonderful Syrah sitting in a carboy with an oak stave, and regret the loss of the rest.

Figuring that prevention is better than cure, I've been making as many plans as I can to avoid this problem this year. Adding 'super food' as well as DAP during primary; increasing punch downs from twice to three times daily. Other than that, not sure what else i can do other than monitor daily and 'splashy' rack at the first sniff of problem.

any ideas?