Copper sulphate additions

[SiSandrine]

Hi,

Someone please check my working out. I am a little confused. I have been using this site http://www.bcawa.ca/winemaking/h2s.htm as my bible for H2S additions pointed to in the recent thread. However it suggests the stock solution of Copper sulphate should be of 0.004% (%w/v) and then 0.1ml of this per litre = 0.1 ppm.

However there seems to be several other sources that disagree with this. The best of which appears to be this site http://vinoenology.com/calculators/f...-oak-addition/.

Plugging the numbers from the first site into this calculator means I would require 9.8ml of 0.004% solution to achieve 0.1ppm in a litre.

This article agrees http://www.extension.iastate.edu/NR/...fatetrial1.pdf


Can anyone see where I am going wrong or is something a little way off here.

Thanks

[NorthernWiner]

I would follow the instructions on the PDF from Iowa State. This is more or less what I do. The only difference is I buy my CuSO4 solution already pre-made.

The 0.004% solution is what you use to conduct the bench trials. This determines how much of the 1% solution you will add to the faulty wine.

Or you can do what I do. Add five drops at a time of the 1% solution to the wine, then stir, then sniff. Repeat until the aroma clears up. Probably best to limit to no more than 50 drops in a 5 gallon batch. If I have to use any more than 20 drops, I then follow with a bentonite fining to remove any residual copper that might be lingering about. Though even 50 drops of 1% solution is well under the threshold that would cause any problems. We consume naturally occurring trace amounts of copper in foods every day.

[SiSandrine]

Thanks Steve