Poppyseed Cellars

Well, the H2S (rotten egg smell) is still with the wine. I tried a side by side trial using copper sulphate fining.

Using a pipette, I put 1 ml of 1% copper sulphate (way more than allowed) into one sample of wine (see picture). In seconds, the H2S smell was gone. This means that the copper sulphate will clear up the problem. I didn’t drink it…

Copper sulphate fining is common in commercial wines, but is not allowed in organically made wines. I don’t want to add it…but at this point it is either add it or pour the wine! imagine being an organic commercial wine maker with 1000 gallons with this problem…what would you do?

Copper sulphate as an additive is allowed 6 ppm (calculated as copper). The maximum residual copper sulphate is 0.5 ppm (as copper). The copper sulphate binds with the H2S, and precipitates out, leaving less copper than you added.

All the books say that 0.15 ml of 1% CuSO4-5H2O per gallon = 0.1 ppm.

• In the 6 gallon carboy I put 0.15 * 6 = 0.90 ml.
• In the 7 gallon carboy I put 0.15 * 7 = 1.05 ml.
• I stirred both carboys. Immediately the nose improved, but I could still detect the H2S. Tomorrow, if I can still smell the H2S, I will put in another 0.1 ppm.

I will do another post later on what is allowed in wine…you would be surprised.

This entry was posted on Tuesday, February 17th, 2009 at 9:13 pm and is filed under 2008 Riebli Valley Syrah. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.