Too Much SO2

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Joe B.

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This is my third year of making from my own grapes and really screwed it up. I copied wine making formals from the Morewine instruction guide on to my wine log to access easily. The problem is I copied the 5 gallon dose of Potassium Met bisulfite down as a 1 gallon for must adjustment. Didn't catch it until after pressing all wines. I racked several times and then had Labs tests run that gave me the following results: Zinfandel 117 total & 25 Free, Barbera 119 Total & 22 free, Grenache 154 total & 20 free all in mg/L. I also had some Syrah that came back 64 total & 17 free that did complete MLF. I am looking for options I have thought of buying concentrate or wine kits and diluting the SO2 but it seems most have So2 added and I have no experience with them. Would like to avoid Hydrogen Peroxided but if someone has had a positive experience please share. As it stands now I don't see MLF completing at these levels. It is 14 gallons Barbera, 8 gallons Zin, and 13 gallons of Grenache. I would hate to see a years worth of vineyard work go literally down the drain.
 
Sorry about your mishap! I can empathize as I've done the same thing (though on a much larger scale...)

In my case we were able to successfully use H2O2 to mitigate the problem. I think the main thing (as with all adjustments, particularly post-fermentation) is to do it gradually, eg calculate your target but don't add the full amount in one go. Here is one protocol: I'm not sure if this is what I used but it's similar:

https://www.awri.com.au/wp-content/uploads/TN06.pdf
 
Late April is when I planed on bottling. Will the bound SO2 also diminish over time?

I don't believe the bound SO2 will diminish. If MLF doesn't happen by next April, it's safe to say it's not going to happen.

A lot of folks focus on the numbers and don't focus on the important things -- what do the wines smell and taste like? If the wines smell and taste good, the numbers are immaterial.

Winemaking is an art. Regardless of how much science we apply, wine is the product of natural substances and processes. We can guide, but control is a fantasy. If it was a science, we could use a formula and produce Chateau Petrus every time.

On the plus side, you made a mistake that you will NEVER make again. Hopefully others will live vicariously through your error and won't do it, either. [We've had several posts recently regarding overdosing K-meta, so it's a common error.]

If we use good hygiene, wine is very forgiving. I expect your wines will turn out better than you currently expect. :)
 
I thank all for the advise and education. I plan on having a little patience and see where it goes from there but will do a trial with H2O2 on a gallon just to see the difference it would make. Your right about it not being a science, the Grenache has the highest SO2 levels but also has the most fruit flavor left in it. You would think it would be just the just the opposite.
 
The bound SO2 certainly won't dissipate. It is bound after all. the free will. I doubt that MLF will be able to happen with that high of a bound SO2, but you can help to ensure it doesn't with a product called Lysozome. If you think this is a wine you will be drinking relatively quickly, I probably wouldn't worry about it, but it is a possibility. What Bryan says is exactly the truth, the smell and taste are so much more important than the numbers. Numbers are guides, not gospel. You will want to keep any SO2 additions at the minimum level for this wine, so that the bound doesn't make it to your threshold of noticing. Everybody has their own level of that and I forget what the average is.
 
happened to me before as well. H2O2 will work and shouldn't cause any adverse problems. not sure why you want/or need your wines to go through MLF anyway unless TA levels are way over 7 mg/l. Use cmason1957 recommendation to use lysozyme which will insure MLB won't do their thing. good luck
 
I looked at lysozyme and it had a wide range of dosage rates. How much is enough? I plan on taking winemaker81's advice and waiting it out but a little insurance would be nice.
 
An update to my original post: Ran Chromatography on all the wines and all have finished except the Grenache and it is in the process showing both Malic and Lactic. I think it will eventually finish also. The fruit flavor has returned to all, and I am optimistic about the potential quality of the wines. I inoculated with B7 Direct MLF culture and for it to complete secondary at these SO2 levels is pretty amazing. I will be racking soon but plan on leaving the fine lees with the Grenache until MLF is complete. It has only been racked off the gross lees to this point. Thanks for all the input it really helped!
 
An update to my original post: Ran Chromatography on all the wines and all have finished except the Grenache and it is in the process showing both Malic and Lactic. I think it will eventually finish also. The fruit flavor has returned to all, and I am optimistic about the potential quality of the wines. I inoculated with B7 Direct MLF culture and for it to complete secondary at these SO2 levels is pretty amazing. I will be racking soon but plan on leaving the fine lees with the Grenache until MLF is complete. It has only been racked off the gross lees to this point. Thanks for all the input it really helped!
Wow, that MLF culture looks really good. I could use enough so2 to protect the wine while it undergoes mlf. Thanks for posting that.
 
I think it was helped by the high PH of the wines. From 3.75 for the Grenache to 4.0 for the Zin. I'm going light of the SO2 in the future and only in the primary until MLF is complete.
 
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