removing SO2 with Hydrogen Proxide

Don,

My two best sources on this question are Lum Eisenman and Ben Rotter. You can find some good information on this question at Ben Rotter's site:

Firstly to clarify, your comment on the dosage of H202 from Jackisch that "0.7 ml of 3% H2O2 to lower it (I think) 20 ppm" should be expressed with the quantity being treated in this case I believe it is 1 gal. Also, when I try to verify the calculation it appears he is referring to 0.7 ml lowering 1 gal by only 10 ppm's. When using H202 you need to be very careful on the dosage. I believe he refers to 1 gal that I assume is a U.S. gal (3.785 liters) and not an Imperial Gallon.

According to my calculations .18 ml (actually .17556 ml) of 3% H202 lowers 1 liter of wine by 10 ppm's free SO2. Again, I think you should check through your own calculations but I am quite confident of these numbers.

The bottom line is:

- Each .18 ml of 3% H2O2 will lower 1 liter by 10 mg/l free SO2.

- Testing the SO2 level before and after H2O2 addition is advised.

- H2O2 should be added slowly.

- There is a limit in the amount of SO2 that can be added as the reaction at low levels produces insignificant amounts of H2SO4 (sulfuric acid) but if too much is added a bitter taste will appear in the wine.

You can use the level I cited above to check the Jackisch dose although I expect they are quite close.

Good luck,

Glen Duff

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D> I don't have a SO2 tester but what is the typical SO2

Glen, Your right in that it was per gallon I forgot to put that in although I was thinking it (half points). I will check the

- do you know the general SO2 level in a kit, real ball park because I don't think I need to bring it down too far. The EC-1118 should have good SO2 tolerance. Maybe I'll just bring it down 10 ppm at a time and give it a small EC-1118 dosage after each.

- Does H2O2 degrade? I have some but it could be year old. Actually I think I will buy new stock but it would be good to know anyhow.

Don

Jackisch did list it as a 10 ppm decrease in SO2 by adding 0.7 ml of 3% H2O2 per gallon of wine. Assuming a US gallon I think.

Still wondering about the probable SO2 level in a finished kit wine. If I remember correctly I've seen the potassium meta package being listed as a 5 gm package. From Jack Keller's page:

Potassium metabisulfite, 1 gram = 150 ppm in 1 gallon, 30 ppm in 5 gallons

That would make it 150 ppm since I split this kit out into a 19l carboy and some 750/375 ml bottles for topping up.

Don

Don,

If I were you I'd pick up a SO2 titrate kit (Ripper method). The cost is not prohibitive although the vials are around 2.50 to 3.00 Canadian per test. The test is simple to do and can be done in a few minutes. I would highly recommend this.

Test the level and let us know. If you're at 150 ppm's you're probably near the upper limit for treating with H2O2 but I think you have a chance. However, a much better alternative is to half the SO2 level by buying another kit and blending. If you need to treat with H2O2 it would require less dosage. Personally I'd consider that possibility as well - a little extra wine never hurt anyone.

Let us know of your next steps, I have empathy for you as I did the same thing last year to two large batches of beautiful Gewurztraminer and Riesling juice. I was in a hurry and did not double check my dosage. I reduced the SO2 level by blending with additional juice, lowering with H2O2 and waiting for the best part of a year as the SO2 decreased. I did try a little splashing. The wine is okay but not nearly as good as it should have been.

Cheers,

Glen Duff

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D> Jackisch did list it as a 10 ppm decrease in SO2 by

Glen, Thanks for all of the information, I appreciate it. The SO2 tester is in the plans as well but no one seems to sell one in Ottawa. Is this the item:

As I mentioned before I tried splashing. I've already bought the lowest end kit I could find to try doubling up but thought I might do the H2O2 method prior to it. I think what I will try over the holidays is another splash racking and a light H2O2. If that does not work I will double up.

Did you switch to EC-1118 or a comparable yeast when you had your problem?

Don

Don,

That is the test although the titrettor normally used with the vial is not shown. It is a holder that is purchased separately and has a lever-type action on the side and the cost is somewhere around $7 or $8. I have never used the titrettes without this in the manner that is shown in the picture. Perhaps others have done so.

You break the lower end of the vial that is under a fine vinyl tube always keeping the tip immersed in the wine once it is broken. A quick release of the lever allows a small amount of the wine to mix with the starch solution. You do this until there is a permanent colour change from blue to a dark-grey or black. The level of SO2 in ppm's is calibrated on the side of the vial and the more wine required to reverse the colour the higher the SO2 level. Instructions come with the vials.

Clearly EC1118 is a good choice for stuck fermentations including higher SO2 levels. In my case the wine had already fermented dry and I was trying a higher than my normal level of SO2 prior to bulk aging since I wanted to avoid MLF and had never had much success preventing MLF with

I would still stress the need to test your SO2 level before trying H2O2.

Good luck,

Glen

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D> Glen,

I have never used a holder for the test. Pushing on the small ball valve will suck wine in.

Not really required. If the little ball valve is not squeezed, nothing will enter at least short term. I've never left one overnight to see if the vacum is preserved.

Or to clear in the case of some white wines.

The more wine required to reverse the initial color change, the lower the ppm of SO2.

Andy

Don, Here is another approach, that is too much SO2 to try to reduce it with peroxide in my opinion; I would want to get it to 100 PPM. The Musca's have a wine store in Ottawa, but I do not know if they sell titrettes. The company that makes them is Chemetrics. The Musca website is Musca.com.

Here is what I might do; pull off 1/3 liter of wine and add water to about 2/3 liter in a 750 bottle. Add 3 or 4 tablespoons of table sugar. Now prepare your yeast (EC1118 is fine, so is K1V1116) and add it to this mix. This would be a starter with half the alcohol and half the SO2; the sugar would allow it to get a good start at fermenting and if it goes, it is somewhat alcohol and SO2 tolerant to begin with. If this gets going well, dump it into the 5 gallons as you have it. (It would be better to do half at a time, but don't risk oxidizing the wine in partially full containers.)

Not knowing your SO2 level makes it harder to know what to do, but you already heard the titrettes are pretty useful, you get 10 per package and I use them. Hope that helps. Regards, Joe