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View Full Version : Using Copper to get rid of Sulfur (possible to use too much?)



PDonn63
07-12-2011, 06:55 PM
This is building off of the other thread I had http://www.gotmead.com/forum/showthread.php?t=18237 titled "Too Much Nutrient." The thread turned more into talking about sulfur than nutrient additions, so I figured I'd post my question about copper in a new thread.

I was unable to find a copper scrub pad to use as a sort of filter on the end of my autosiphon as medsen suggests, so I stripped a foot of speaker wire and used the copper innards to line my siphon hose. I splash racracked the cider/apple wine through twice, but still smell some sulfur today (though not quite as much). Instead of racking again and losing more of the product (it's been racked 3 times and its only 5 weeks old), I have some of the copper soaking in the carboy (about 3 inches of copper wire).

Are there any negative consequences to over-using copper; and will soaking it help as opposed to using it when racking?

All help in saving this batch's aroma is greatly appreciated.

wildoates
07-12-2011, 07:16 PM
I'll let the experts chime in with the real skinny, but will tell you my experience with copper: I use copper shot because it's what I have. I've had to dose 3 or 4 batches with the copper, and each time I put it in the toe of a knee-high stocking and racked the mead through it. That's never been enough, so what I ended up doing was just hanging the stocking in the mead--swishing it around from time to time--until the S smell was pretty much gone, as long as 2 days. Then I racked it with a bit of gentle splashing et viola! It did the trick.

The only time it didn't do the trick was with the cyser; it continued tossing sulfur for days after I racked it into a carboy, which I gave a shake to every time I walked by. Eventually it all degassed out and all was well.

kudapucat
07-12-2011, 07:19 PM
Copper will react with your mead no mater how it's in contact.
It will stop reacting when it has effected all the volatiles and acids in your batch.
I wouldn't leave it in there forever, in case you end up with a copper oxide or copper sulphate or whatever it turns into taste.
In fact if the brew has lessened sulphur aromas now, I'd age it without copper for a month and see how you go. Then add some small amount (like you have now)
But don't leave it in there until the smell is gone, you may overdo it that way. Just do it in small doses at a time. And use fresh copper, keep all the oxides and crap that turn the wire black/blue/green out if you can.
Copper wire that has discoloured will be less effective too, as the oxides provide a barrier between the copper and the mead.
Hope this helps.

Disclaimer: my advice is based on my chemistry experience only, not mead experience, I've never had sulphur aromas.

wildoates
07-12-2011, 07:31 PM
Triple-ought steel wool is your friend if your copper needs refreshing (although mine has always come out of the mead shiny as a new penny).

kudapucat
07-12-2011, 07:41 PM
Triple-ought steel wool is your friend if your copper needs refreshing (although mine has always come out of the mead shiny as a new penny).

Hmmm hence my disclaimer,.... it appears the copper is an anode in this case, adding stuff to your mead (that will hopefully precipitate out, and be left behind when you rack) which makes sence in an acidic environment.

wildoates
07-12-2011, 07:45 PM
It does react with the sulfur to form an insoluble precipitate, which then drops down to the bottom eventually. I first assumed the copper was a catalyst, but it's not.

Chemistry is not my strong suit, which is why I don't teach it. :)

kudapucat
07-12-2011, 07:53 PM
It does react with the sulfur to form an insoluble precipitate, which then drops down to the bottom eventually. I first assumed the copper was a catalyst, but it's not.

nah, most metals are active in reactions, and either grow or erode.


Chemistry is not my strong suit, which is why I don't teach it. :)

Same here, but I try. Certainly I couldn't teach it, I've been asked to tutor a few times, but I just wont go near it. Maths, Engineering, Software, Automation... sure, any time ;-) these things make sense

Riverat
07-12-2011, 08:24 PM
Somebody double check me....2 Cu+2 H2S=2 h2 + 2 Cu2S?....is the sulfur in mead HS, H2S, it's not Hydrogen sulfate is it?.........

There once was a student of chemistry
Alas he is no more
For what he thought was H2O
Was H2SO4!

BMB
07-12-2011, 09:23 PM
Yeah, hydrogen sulfate would just be the conjugate base (HSO4-) of sulfuric acid, (H2SO4) after its first proton dissociation. I'd imagine the copper would precipitate out the sulfur in the form of CuS, which has an extremely low Ksp value; meaning it's very negligibly soluble in water (For all intents and purposes here, non-soluble). Perhaps there are other intermediate steps involving complex ion formations and whatnot, but I'll leave that to the smarter nerds on the board. ;)

storm1969
07-12-2011, 09:55 PM
The couple of times I have have to remove the sulfur smell I have racked through a 2 foot length of copper pipe. It has always worked.

Loadnabox
07-13-2011, 08:34 AM
I had to go to a dollar store to find the copper scrub pads. Regular stores didn't have them.

It's also interesting to note that it isn't a catalyst which I was also apparently mistaken about. This explains a lot as I have only "Copper Plated" scrub pads. The wine completely stripped one scrub pad of it's copper coating. I've been thinking of going for the copper tube in the funnel for future attempts at racking the mead that needs copper treatment. It worried me when the steel under the copper rusted from the acidic wine :( Good thiing it wasn't in contact very long.

Dan McFeeley
07-13-2011, 09:38 AM
I wonder if a copper stir rod might be more convenient -- easy enough to make, a length of copper tubing should work.

--

havoc64
07-13-2011, 05:18 PM
I had a slight sulfur smell and it was suggested by Wayneb that I try the copper treatment. I went to Lowes and bought a 2 foot long 1/2" copper tube. I scrubbed the tube and then sanitized it in some One Step. Then I ran the mead down the outside of the tube letting it collect in a sanitized ferm bucket. I stirred it a little and then let it off gas overnight in an air locked carboy.

Next morning, no Sulfur smell!

Easy Peezy lemon Squeezy

wildoates
07-14-2011, 01:16 AM
I like copper inside the racking cane idea.