SO2 and H2O2 (sulphite and peroxide)

[katzgejm]

so i made the mistake of distilling a cider that had been sulphited, and the SO2 was unbearable on the nose. copper, it turns out, doesn't react out sulphites. more details on all that in this thread: http://homedistiller.org/forum/viewtopi ... 38&t=60464

it was suggested to add H2O2 (hydrogen peroxide) to the low wines at a rate of 10ml/L. apparently this reacts out to sulphiric acid and water. sulphiric acid's boiling point is 337C, peroxide 150C, water 100C. so no need to worry about any coming over in the next run (right?)

so my first question is, why not add a generous amount of H2O2 to be sure to react out all of the SO2? any peroxide that doesn't react should stay in the boiler, no?

second question relates to this equation: Cu + 2 H2SO4 ==> CuSO4 + SO2 + 2 H2O
if i'm reading this right (good chance i'm not), if there's copper in your boiler, you're going to react that sulphiric acid right back into sulphur dioxide!

what am i missing here?

[GrassHopper]

so i made the mistake of distilling a cider that had been sulphited, and the SO2 was unbearable on the nose. copper, it turns out, doesn't react out sulphites. more details on all that in this thread: http://homedistiller.org/forum/viewtopi ... 38&t=60464

it was suggested to add H2O2 (hydrogen peroxide) to the low wines at a rate of 10ml/L. apparently this reacts out to sulphiric acid and water. sulphiric acid's boiling point is 337C, peroxide 150C, water 100C. so no need to worry about any coming over in the next run (right?)

so my first question is, why not add a generous amount of H2O2 to be sure to react out all of the SO2? any peroxide that doesn't react should stay in the boiler, no?

second question relates to this equation: Cu + 2 H2SO4 ==> CuSO4 + SO2 + 2 H2O
if i'm reading this right (good chance i'm not), if there's copper in your boiler, you're going to react that sulphiric acid right back into sulphur dioxide!

what am i missing here?

I think your equation is correct. You would end up with copper sulfate, sulfur dioxide, and peroxide as you show. But, the reactions would only be a percentage of the overall contact with the elements involved. So, it would be a percentage of the contact of the vapor to the copper on the way to the condenser. I think I read somewhere once how to calculate that. I also think I remember getting an F on that particular part of the course.
Why not just ferment some good stuff?

[still_stirrin]

Plus, the goal is to reduce sulphur production in the ferment. If you don't have much sulphur, there isn't much to worry about in the distillate.
ss

[thecroweater]

I know I've said this before but I would like to see some evidence that sulphite doesn't react with copper. That has not been my experience nor the experience of anyone I know. Metabisulphite is a common inhibitor with harvested grapes and those grapes make a fine brandy in a copper still . As I said right at the start your result was typical of not enough copper and sure enough you ran a stainless still. hydrogen peroxide is not something I would deliberately add to anything i was going to still. Firstly as I understand heating hydrogen peroxide with a reducing agent like metabisulphite or any sulphite compound is pretty dangerous and can cause a violent reaction also a number of unwanted compounds can form like acetone peroxide so popular for making IEDs think London bombings. really this whole crazy idea sounds like something for the what not to do thread to me

[Bushman]

it was suggested to add H2O2 (hydrogen peroxide) to the low wines at a rate of 10ml/L. apparently this reacts out to sulphiric acid and water. sulphiric acid's boiling point is 337C, peroxide 150C, water 100C. so no need to worry about any coming over in the next run (right?)

Can you share where this information comes from?

[LWTCS]

I thought it was relatively well known that hydrogen peroxide can sequester sulfides?

It is a technique that wine makers use regularly.
I have the formula from a well known source within the pro ranks at the office. In the mean time here is an article that was first to pop when googled:

http://www.wired.com/2015/06/wine-sulfi ... ve-anyway/" onclick="window.open(this.href);return false;" rel="nofollow

[thecroweater]

True but I'm not sure turning metabisulfite into sodium bisulfate is any sort of great leap forward regarding distillation, we are not trying to ameliorate a pungent red here

[pfshine]

While I'm sure you aren't going to blow your selves up with this venture. There could be a very large exothermic reaction to be aware of. H2O2 is a powerful oxidizer used in lots of bombs and fuels. The reactions you are looking for create some really nasty chems. I would abandon the whole thing if I were you

[thecroweater]

While I'm sure you aren't going to blow your selves up with this venture. There could be a very large exothermic reaction to be aware of. H2O2 is a powerful oxidizer used in lots of bombs and fuels. The reactions you are looking for create some really nasty chems. I would abandon the whole thing if I were you

Thankyou pfshine I have been waiting for you and your expertise to show up

[GrassHopper]

This is good stuff. How do I make some bombs? I promise, I'm not with ISIS.

[thecroweater]

Listen guys you have a metabisulfite solution in the presence of acetone, acetate and ethanol and are discussing adding hydrogen peroxide before boiling it. I'm not into censorship but this is starting to sound bloody dangerous to me, if there isn't a credible why this is ok I'm going to lock this out of safety concerns. The more I look into this the more uncool it seems