Ducking Sulfur

[citizensnips]

Howdy all,

Recently brewed a Hefe with 3068 which has been kegged and carbonated. After pouring a glass there is a reasonably strong smell of sulfur that comes ahead of the typical hefe aromas. It's pissing me right of as only a few months ago I had to tip my first batch ever of all grain due to sulfur that was way to overpowering in a kolsch. I'm looking for thoughts on how to attack this as everything else about the beer is spot on. As I said it is already chilled and fully carbed. I've been reading about having copper in the kettle or immersion chiller etc..and am thinking about that. But for the time being has anyone had any luck with the following

- Adding copper to the keg of finished beer to eradicate the smell
- Just venting co2 regularly
- co2 scrubbing
- Or just being patient and somehow hoping it dissipates into the beer.

P.s. it was left in the fermenter for more than enough time along with the yeast temp being brought up towards the end of fermentation.

Any thoughts or experience would be appreciated

Cheers

 

[Beamer]

Hey mate, I use kolsch as one of my house yeast, and I find it to get rid of the sulfur completely I cold condition the keg for 3-4 weeks and then carb.

I dont have much experience with hefe yeast.

 

[MHB]

Hefe yeast is probably the only brewing yeast that cant metabolise sulphur, it just doesn't have the genes for the job.
If you have a Sulphur problem with A Hefeweizen - look elsewhere.
From what you have said I think it sounds like yeast autolysis might be a better prospect.

Adding Cu wont help.
Venting - stripping (same thing) might remove some smell, but is guaranteed to remove some of the lovely Hefe aromas to
Also probably the least likely style to improve with maturity (best young).

Good Hefe should be made fast (fermented in 7 days), short maturation/carbonation (7 days) and ideally consumed in the next (u guessed it)
Sitting around in the fermenter for extended primary and/or secondary ferments isn't the way to make great hefeweizen.

Mark

 

[MastersBrewery]

What Mark said. Also 3068 is one of those yeasts that I like to abuse a little, slight under pitch and run warm (20-22c) helps push those phenols and ensures a qick ferment.

 

[Lyrebird_Cycles]

Just so we are clear, by "the smell of sulphur" do you mean the smell of sulphite (brimstone) or the smell of sulphide (rotten eggs)?

If the former, I agree with the above that when fermented at correct temperature (22 - 23 C) W68 does not form endogenous SO2. I can't remember it forming SO2 at other temps but we only ever did lab scale trials at other temps so I may be a bit hazy there. SO2 is of course not amenable to copper fining. Every time I've seen this it's been a cellar addition at fault, is there any chance that anything was "sterilised" with bisulphite solution?

If you mean sulphide it can easily be formed by stressed yeast and yes it might be cleared up by judicious use of copper fining: do a bench trial with copper sulphate solution, say 0.1 0.25, 0.5, 1, 2 ppm As Cu2+ (multiply by 4 for copper sulphate eg 4mg copper sulphate per litre is 1 ppm Cu2+). Do a further trial between the lowest rate that removes the sulphide and the next one down. If the problem is still there at 2 ppm you're not going to shift it with copper, you could try oxygenated yeast lees (if you want to try this ask and I'll run you through the process, quite fun to do).

BTW I refuse to taste copper trials and do them on smell alone but most other people are OK with tasting them.

The copper addition can be done very late but the beer should be fined / filtered after a copper addition to remove the copper sulphide. We used to have a copper plate bolted into the filter room hard line with a constant current source, if I smelt sulphide I just turned up the current until it went away. This was after the earth filter and before the sterile filter so that the assessment was made on clean beer but the sterile would remove the CuS.

 

[drsmurto]

Are you referring to hydrogen sulfide when you say sulfur? Think boiled eggs or in high doses, rotten eggs?

If so then copper sulfate can remove it. It's used quite a bit in the wine industry. You would normally buy the pentahydrate CuSO4.5H2O from wine supply shops. Add it at a rate of 0.5mg/L. The effect is instantaneous.

Edit - beaten to it! But recent research has shown (in wine) that filtering does not remove the CuS formed and that it is unlikely to be just CuS due to the other compounds available to interact with the copper.

 

[Lyrebird_Cycles]

That's interesting: when we add Cu just before bottling it doesn't doesn't show up in the post bottling QA unless someone stuffed up the trials or the cellar added too much. Sterile filter into bottling line has been assumed to be the cause.

 

[klangers]

I'm under the impression that most copper solutions are toxic.

However, everything's a poison; it's the dose that matters.

 

[MHB]

Just done a bit of searching through ANZ Food Standards.
As far as I can tell Copper Sulphate is a permitted additive in wine making.
Not permitted in beer, wont stop home brewers using it but I would be very cautious.

Have also run a search through most of the more recent brewing texts I have to hand (Kunze, Brewing Science and Practice, Handbook of Brewing...)
Nada, no mention of Copper as an additive or fining, just the well known - copper is a required micro nutrient for yeast and toxic to yeast over 10mg/L.

I would be extremely cautious adding copper at any point in wort production, if you feel you must add copper make sure you stay well under 10mg/L before fermentation. Post fermentation, well it is a toxic cumulative heavy metal, note to that yeast (Saccharomyces) is much more sensitive to Cu than are wild yeast and many other bacteria and spoilage organisms. One way to test for wild yeast is to make an agar plate with Cu, Brewing Yeast wont grow, bugs (most) will.
Mark

 

[Bribie G]

Hydrogen SulPHide is actually a bit of a signature in the aroma of many Euro lagers when you pop the top of the bottle and get that nice hoppy whiff that screams "German, Czech" etc. Nearly all of it is cleared during a long lagering process.

 

[Lyrebird_Cycles]

Just done a bit of searching through ANZ Food Standards.


As far as I can tell Copper Sulphate is a permitted additive in wine making.
Not permitted in beer, wont stop home brewers using it but I would be very cautious.

snip

if you feel you must add copper make sure you stay well under 10mg/L before fermentation


Mark

As stated above, the way around that impediment is to use a copper plate as the anode in a closed cell, legally you aren't adding copper. Helps to have an AA in house so you can check that physically you aren't adding copper either.

Copper causes oligodynamism in yeast, its presence before fermentation is likely to lead to more problems than simple sulphide levels. Occasionally happens in wine if "Bordeaux mixture" is used too close to harvest.

 

[MHB]

Your a wine maker - right...
Mark

 

[Lyrebird_Cycles]

Was. Was also a (paid) brewer and had a stint in a maltings.

I now make bicycles.

 

[drsmurto]

As pointed out, using copper metal in brewing does not involve 'adding copper' to your beer and as such, is technically legal. One of my colleagues is ex-Fosters and talked about a copper rod that was used just before the filter to strip sulfides (not sulphides Bribie, the IUPAC spelling is sulfides - there has been a lot of research into the spelling and it turns out the brits got it wrong, the 'american' spelling is actually correct. Yes, it saddens me to admit the seppos can spell). In winemaking copper sulfate is a legally permitted additive but in the past 5 years or so we've been showing that it does a lot more than winemkakers have been led to believe, in particular the practice of adding it before bottling as a 'just in case'.

I suspect that by filtering immediately after treating with Cu doesn't allow the CuS formed to interact with any other species in wine/beer which means it can be filtered although you would need to be using 0.1-0.2um filters, not 0.45um. A quick experiment I've done is to show that CuS, classified as insoluble, dissolves in wine into free Cu++ and S-- ions, the latter then reacts with wine molecules to form H2S and other S containing compounds. Might grab a bottle of beer to see how this works compared to wine.

If you add it to wine/beer and then leave it there for days/weeks before packaging then that's where the problems are likely to arise.

@Lyrebird - AA doesn't have a particularly great LOD. 0.1ppm or thereabouts. I use ICPMS for metal analysis and the LOD for copper is around 0.005ppm. At that resolution you pick up a lot and given copper is catalytic in the redox cycles, you only need a very small quantity for chemistry to occur, particularly in beer where there are less organic molecules likely to interact with the copper as compared to wine.

 

[citizensnips]

Thanks very much for the detailed replies. I'm referring to sulphur as in the egg smell or what is commonly smelled when you're at a natural spring.
So it seems even adding a piece of copper to the Keg would not suffice in reducing the sulphur Aroma. It appears a few of you have had a bit of luck with just time and cold conditioning, so this may be my best option. If this doesn't work I may continue to bleed the keg or look into CO2 scrubbing as I'd rather have a beer with little Aroma that one that smells like a fart.

 

[Lyrebird_Cycles]

As pointed out, using copper metal in brewing does not involve 'adding copper' to your beer and as such, is technically legal. One of my colleagues is ex-Fosters and talked about a copper rod that was used just before the filter to strip sulfides


snip


@Lyrebird - AA doesn't have a particularly great LOD. 0.1ppm or thereabouts. I use ICPMS for metal analysis and the LOD for copper is around 0.005ppm. At that resolution you pick up a lot and given copper is catalytic in the redox cycles, you only need a very small quantity for chemistry to occur, particularly in beer where there are less organic molecules likely to interact with the copper as compared to wine.

As posted above, the copper rod or plate is attached to a constant current source that does the work. Whether it's boiling off copper cations or absorbing suphide anions is the legal question.

Re the spelling, apparently the ph spellings in English came about because Dr Johnson thought they made it more classical (Greek phi), also cleared up confusion caused by the Elizabethan habit of spelling the soft s or ss as script f.

My first job out of Uni was running an AA for a research group in Sydney, I'm pretty sure our LODs were better than 0.1ppm but that was a long time ago. More recently wineries have moved to instruments like MP-AES, I believe the LOD is 0.5 ug/l (0.5ppb)

I take it you are doing a PhD with the Smith group at AWRI?

 

[Lyrebird_Cycles]

Thanks very much for the detailed replies. I'm referring to sulphur as in the egg smell or what is commonly smelled when you're at a natural spring.
So it seems even adding a piece of copper to the Keg would not suffice in reducing the sulphur Aroma. It appears a few of you have had a bit of luck with just time and cold conditioning, so this may be my best option. If this doesn't work I may continue to bleed the keg or look into CO2 scrubbing as I'd rather have a beer with little Aroma that one that smells like a fart.

If you don't want to do a fining trial with copper sulphate you could try getting a low voltage power supply (say 5 Volt 1 amp), attach the +ve to a piece of copper and the -ve to your keg and dangle the copper in the keg DON'T LET IT TOUCH THE SIDES. Leave it for a minute or two then pull it out and swirl the keg, if it still stinks repeat.

 

[citizensnips]

Appreciate the suggestion however I barely understand amps let alone dangling electric copper in in steel keg, think I'll stick to more basic approaches. Nonetheless appreciate the suggestion, cheers

 

[drsmurto]

As posted above, the copper rod or plate is attached to a constant current source that does the work. Whether it's boiling off copper cations or absorbing suphide anions is the legal question.

Re the spelling, apparently the ph spellings in English came about because Dr Johnson thought they made it more classical (Greek phi), also cleared up confusion caused by the Elizabethan habit of spelling the soft s or ss as script f.

My first job out of Uni was running an AA for a research group in Sydney, I'm pretty sure our LODs were better than 0.1ppm but that was a long time ago. More recently wineries have moved to instruments like MP-AES, I believe the LOD is 0.5 ug/l (0.5ppb)

I take it you are doing a PhD with the Smith group at AWRI?

PhD student? I wish. They were the days. :chug:

I did my PhD 15 years ago (the acknowledgement section in my thesis included a line thanking Andrea @ the Unibar, the dispenser of many, many beers in my 9 years at uni).

 

[Lyrebird_Cycles]

OK, no slight was intended. If you are with the AWRI, chapeau, you people are great.