[hulkavitch]

Just bottled a ag bavarian hefe today. Wyeast 3068 Fermented at 62 for 14 days with a chest freezer and johnson controller. Did not realize until after i had bottled and i was sampling my hydrometer sample that it had a horrible sulfur odor. It tastes good, it just stinks.  In retrospect i would have brought the temp into the 70s after 10 days and hopefully clean it up.

I have read that sulfur odors dont go away in the bottle, is that true? What has been your experience with this?

[nateo]

My last batch of Hefe with 3333 had a bit of sulfur when I bottled it. It wasn't noticeable once the beer was carbed, though. As long as you're bottle conditioning you should be OK.

[hulkavitch]

Yeah i figure i will leave it in bottle for a few 2-3 weeks.

[Kaiser]

Yes, it should age out. There isn't much else that's practical anyway.

btw, it's not the yeast that reduces the sulfur notes that you are talking about. if I remember correctly it's actually oxidation. That's why sulfur helps beer stability. But I agree that this aroma is very distracting.

Kai

[majorvices]

I disagree that sulfur ages out. It will out gas in the glass once it is poured, but it will not age out. One trick I have found that works well is to run the beer through a piece of copper when racking. This takes away a lot of the sulfur. Or, of course, you can bubble Co2 through the beer but it will also strip away a lot of the beers aromatics.

Sulfur is generate by the yeast and I have had problems with certain wheat beer strains, but I wonder if there isn't something about the wheat malt itself that causes the yeast to generate the sufur. I always add a good nutrient now to my wheat beers and that seems to have taken care of the problem.

[hulkavitch]

I used  a yeast nutrient on this brew. It had a strong sulfur smell throughout fermentation and at bottling.

If i would have smelled/tasted my hydrometer sample prior to it being in bottles i wouldnt have bottled it.

next time after my fermentation is finished i am going to allow it to warm up to room temp instead of continuing to control at 62.

I was pretty sure it was finished I checked gravitys on mon and tues (days 10 and 11) and again on friday (day 14 the day i bottled)  I thought that the 4 extra days was plenty of time for the yeast to clean up? Started 1.053 ended 1.013-14

Kai I did aerate the hell out of it, but thats a good thing before pitching right? So sulfur is quiet normal?

[nateo]

Sulfur dioxide is widely used in large quantities as an anti-microbial and anti-oxidant in winemaking. Sulfur is naturally produced by most (maybe all?) S. cerevisiae yeasts during fermentation. It doesn't readily bind to oxygen, but it does readily bind to oxidation byproducts and polyphenols. It also binds with acetaldehyde. Once bound, it becomes flavor- and odor-less.

It definitely ages out with time. How much time it takes may be in issue. No one wants to drink a year-old Hefe.

As Keith mentioned, exposing the beer to copper should knock down the sulfur. SO2 readily binds with polyphenol oxidase, which is mostly copper atoms.

[tomsawyer]

I'd leave the beer in a carboy or bucket for another week to give the sulfide time to gas out.  I'd even be tempted to stir it a time or two.  Bottling is going to capture the H2S and the only way it dissipates in that case is through oxidation.

You add potassium metabisulfite to wine and some small amount of that converts to sulfur dioxide, the amount of SO2 is pH dependent.  Above pH of 4.0 almost none becomes sulfur dioxide and the wine is not protected from spoilage organisms.

Morewine sells a product called Reduless, its a copper salt bound to a yeast hull and it is a good treatment for moderate hydrogen sulfide levels.  I haven't heard of it being used in beer but I don't see why it wouldn't be effective.

On the other hand I've had a few stinky wheat beers and they always ended up OK as long as I gave them time.  I always thought it was a lack of enough amino acid nitrogen, figuring that wheat didn't have as much FAN as barley malt.  Maybe the weizen yeasts have a higher requirement, certainly there are some wine yeasts (like RC212) that have a high nutrient requirement and are prone to H2S production.

[hulkavitch]

Update: 1 week in bottles carbing nicely. Sulfur already diminshed still can smell and taste slightly.

[roguejim]

Yes, it should age out. There isn't much else that's practical anyway.

btw, it's not the yeast that reduces the sulfur notes that you are talking about. if I remember correctly it's actually oxidation. That's why sulfur helps beer stability. But I agree that this aroma is very distracting.

Kai

So, do you let it age out in the fermentation vessel before kegging?  Is there any way to avoid this right from the start?  I dumped almost an entire kegged dunkelweizen due to sulphur.

[majorvices]

In my experience it doesn't age out once it is packaged, or if it does it takes months. Best bet seems to be to let C02 drive it out of suspension, or try copper trick mentioned above.

[Kaiser]

The production of SO2 by the yeast is something that interests me quite a bit since it can be rather annoying when I look for fast turnaround of lagers. Given time it will go away, so I don’t see it as a big problem.

Turns out that there has also a bunch of research on this since SO2 in beer has been linked to better stability due to the O2 scavenging that SO2 does. Because of that breweries may look for procedures that increase SO2 production.

Here is an interesting chart I found in a lecture presentation at Weihenstephan brewing school. It compares the SO2 production of lager yeast. Using  Kristen England’s yeast comparison chart and Google searches I was able to identify some familiar strains:



Kai

[nateo]

Kai - Have you come across anything in the brewing lit. that talks about SO2 and acetaldehyde? I've only seen that connection made in winemaking sources.

[hopfenundmalz]

The guy who did the research on the history of lager yeast from South America was skyped into the BJCP reception at the NHC. Some yeasts have genes that he called the SUL1 and SUL2 sulfate transport genes, which allow the sulfate in and sulfite out - or something like that.

Maybe Tom can chime in on that, as that is in his area of expertise.

[Kaiser]

Kai - Have you come across anything in the brewing lit. that talks about SO2 and acetaldehyde? I've only seen that connection made in winemaking sources.

In the presentation the chart is from there is some mention of SO2 being bound to acetaldehyde and that this bond is reversible. Meaning that SO2 doesn't have to be free to show its O2 reduction potential.

Not having delved too deeply into the science of this, but does this suggest that acetaldehyde helps with the reduction of fee SO2 and does this SO2 get freed again when acetaldehyde is consumed by the yeast during maturation?

Kai