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General Category => Yeast and Fermentation => Topic started by: wingnut on December 11, 2010, 04:03:37 AM

Title: Process/Yeast change to reduce sulfur in finished beer
Post by: wingnut on December 11, 2010, 04:03:37 AM
So I am sipping my last batch of Vienna lager… pondering what to do different as I compare it to a number of commercial examples.   

I like the malt flavor, and I like the hop balance, but the Sulfur characteristic I am getting from the Whitelabs 833 yeast is a bit higher than I would like compared to the samples I am comparing it to. 

So with that in mind, is anyone aware of mashing processes for reducing sulfur or different yeasts that give off a great malty flavor, but with less sulfur?   I am brewing the next batch in a couple weeks, so any advice to ponder now while I formulate the next recipe would be much appreciated!
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: tom on December 11, 2010, 05:29:48 AM
Weird, I haven't had sulfur with that yeast. What gravity, oxygenation, starter size, and fermentation temperature did you use?
What kind of sulfur? rotten egg? burnt match?
Occasionally releasing the carbonation may release enough.
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: tygo on December 11, 2010, 05:53:09 AM
I'm currently drinking a BoPils fermented with 833 and I've noted some sulfur as well.  It's just barely noticeable and really not unpleasant at all.  Actually adds some character to the beer.  More the burnt match than the rotten egg variety :)
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: Kaiser on December 11, 2010, 12:28:45 PM
How old are these beers.

Sulfur goes away with age.

Kai
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: tygo on December 11, 2010, 01:06:56 PM
Mine was brewed on 10/3.  Two weeks (or so) primary, four (or so) weeks of lagering, and about 3.5 weeks in the bottle so far. 
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: gordonstrong on December 11, 2010, 01:59:14 PM
I use 833 all the time and think it's actually fairly low in sulfur.  Compare it to 820, for instance.

Mashing doesn't really affect sulfur.  It's something yeast produce, and lager yeast produce more.  Certain strains are known to be higher producers than others.

How do you lager?  It does tend to come out a bit then, so if you are blowing off the sulfur during lagering, it will help.  Some people perceive yeast itself as sulfury, so you can also try fining with gelatin towards the end of your lagering period before packaging.  It does tend to reduce over time, as Kai said.  But it's better to keep it down if you can.  Choose low sulfur producers, let it blow off, age it out.
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: wingnut on December 11, 2010, 03:08:18 PM
I should probably clarify a bit...

To start, the beer I am brewing, I have been brewing for about four years now and I have somewhere around 15 to 20 batches of it under my belt.  It is the beer that I change one thing at a time on and compare the results to help learn how to dial in beers.  I am placing in competitions with it, so the sulfur I am talking about is not a “knock you over” sulfur... but in doing triangle tests with some commercial examples, I find that I am preferring those commercial examples and I am picking out an elevated sulfur odor in my version that I not present in the commercial examples.  It is not bad, just different.  So in the next batch or two I thought I would work on dialing in that aspect. 

Process is one vial of 833, into a 2L starter, put on stir plate for three days at 70F.  Then either pitch into wort or store flask in fridge for up to two days before pitching into wort.  (sometimes life changes my brew day on me!)

Sometimes I pitch the whole starter, other times I pitch just the sediment...into 5.5 gallons of wort at 1.056 to 1.060

Ferment at 50F to 55F for two to three weeks, rack into corney keg, and lager for 4 to 8 weeks at 35 to 38F. 

I do not fine the beer, and it usually drops clear in that time. 

I do not off gas the corney during lagering, so that may be a start... is the proper process to push in some CO2 and then let it out, just to purge the head space?

Any other procedures for keeping the sulfur low during fermentation/mashing/etc would be appreciated!

Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: Kaiser on December 12, 2010, 03:35:16 AM
Sulfur, and th time it takes to remove it, bothers me too, It is like you said not something that hits you in the face but something subtle that is best noticed in side-by-side taste comparisons. Do far I have not done anything special to reduce the sulfur. Just waiting has worked for me but I'm keeping my eyes open for ways to reduce or speed up the sulfur reduction. Gordan's tip with gas washing the beer is something I have come across before but it also means that I have to attend the beer more than I would normally do.

Kai
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: dmtaylor on December 12, 2010, 01:01:59 PM
Sulfur has always disappeared with age for me.  Usually it is totally gone after about 3 or 4 weeks.  However, one time I had a light lager where the sulfur was still there for months.  So I sort of gave up on it, let it age for over a year, then went back to it.  Sulfur was completely gone after that extent of time, and it ended up being a pretty tasty beer despite its age.

Patience.
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: oscarvan on December 12, 2010, 04:03:27 PM
Excuse the noob..... but would it help to put a piece of copper in the secondary?
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: denny on December 12, 2010, 07:05:43 PM
Excuse the noob..... but would it help to put a piece of copper in the secondary?

I don't know the correlation between copper and sulfur, but I wouldn't do it.  The low pH of the beer will cause problems with copper.
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: Kaiser on December 12, 2010, 07:26:22 PM
Excuse the noob..... but would it help to put a piece of copper in the secondary?

I came across the correaltion between copper and lower sulfur when I was reading up on the subject last night. However I agree with Denny that you may get more issues than you solve. There is also the possible formation of toxic copper sulfate.

Kai
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: Thirsty_Monk on December 12, 2010, 11:44:15 PM
Would different fermentation schedule help with elimination sulfur in the first place?
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: James Lorden on December 13, 2010, 02:40:43 PM
Does yeast stress cause more sulfer to be produced?  I was under the impression that underpitching a lager could lead to more sulfer.  Is that a true statement... I can try to identify my source, working off memory here.
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: Thirsty_Monk on December 13, 2010, 02:56:19 PM
Does yeast stress cause more sulfer to be produced?

That is my understanding that stressed yeast is producing sulphur.
What would be the stress factors?
Underpitching is one of them.
How about fermenting too cold?
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: gordonstrong on December 13, 2010, 05:36:04 PM
Sulfur, and th time it takes to remove it, bothers me too, It is like you said not something that hits you in the face but something subtle that is best noticed in side-by-side taste comparisons. Do far I have not done anything special to reduce the sulfur. Just waiting has worked for me but I'm keeping my eyes open for ways to reduce or speed up the sulfur reduction. Gordan's tip with gas washing the beer is something I have come across before but it also means that I have to attend the beer more than I would normally do.

Kai

Actually, I'm not gas washing the beer; I'm talking about putting a pressure-relief attachment on the gas post and letting the excess pressure bleed off as it's produced.  It's better for the yeast not to have that excess pressure on it anyway.  Rocking the keg occasionally to knock some of the CO2 out of solution also helps.  I don't like attending to the beer much either, so I try to use alternatives where possible.
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: James Lorden on December 13, 2010, 05:59:39 PM
This is a paper written by Shea Comfort relating to the formation of sulpher by yeast in wine.  Under Oxygenating seems to be a major contributor (at least in wine).  I would think that could also apply to beer.


UPDATE TO INCLUDE LINK

http://www.yeastwhisperer.com/uploads/YeastWhisp_Oxy_Ferm_fin_.pdf
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: Kaiser on December 13, 2010, 06:43:08 PM
Actually, I'm not gas washing the beer; I'm talking about putting a pressure-relief attachment on the gas post and letting the excess pressure bleed off as it's produced.

That has been my process as well. But with this process you only get the washing action of the CO2 that is produced. The technique that I was referring to actually uses additional CO2 to wash the sulfur aroma out of the beer. I thought you referred to that.

Kai
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: ipaguy on December 13, 2010, 06:51:11 PM
This is a paper written by Shea Comfort relating to the formation of sulpher by yeast in wine.  Under Oxygenating seems to be a major contributor (at least in wine).  I would think that could also apply to beer.

Was there supposed to be a link for this?  I'm curious  about the mechanism here.  Obviously, no yeast is going to actually 'produce' sulfur.  Yeast are incapable of transmuting elements (like lead into gold).  It would be nice to know what sources of sulfur the yeast can use to produce H2S (rotten eggs) or SO2 (burnt match).  If sulfate is a possible source then water chemistry would be something to look at.  If sulfur containing proteins or amino acids are candidates it might be good to look at malt type, protein rest, and boil conditions.  I believe that you want to try to convert most of your organic sulfur compounds to DMS and drive that out in the boil.  I admit ignorance on these questions, but am really curious about the chemistry involved.
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: gordonstrong on December 13, 2010, 06:51:23 PM
Actually, I'm not gas washing the beer; I'm talking about putting a pressure-relief attachment on the gas post and letting the excess pressure bleed off as it's produced.

That has been my process as well. But with this process you only get the washing action of the CO2 that is produced. The technique that I was referring to actually uses additional CO2 to wash the sulfur aroma out of the beer. I thought you referred to that.

Kai

Right; I figured that's what you meant.  I don't really know how to do that without carbonating the beer; it must be something that is done after lagering is done.  Otherwise, by adding CO2 while the beer is cold would increase carbonation and stress the yeast more.  Or would you do that at a warmer temperature to encourage the CO2 to stay out of solution?
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: James Lorden on December 13, 2010, 08:00:55 PM
This is a paper written by Shea Comfort relating to the formation of sulpher by yeast in wine.  Under Oxygenating seems to be a major contributor (at least in wine).  I would think that could also apply to beer.

Was there supposed to be a link for this?

Yes, sorry

http://www.yeastwhisperer.com/uploads/YeastWhisp_Oxy_Ferm_fin_.pdf
Title: Re: Process/Yeast change to reduce sulfur in finished beer
Post by: wingnut on December 17, 2010, 05:25:48 PM
Hmm.... Looks like I will try a bit more O2 on this next batch.   I have been aerating with an aquarium pump and stone up until now, perhapse I will take the dive into O2 injection for the next batch as the process point I am changing and see how big a difference it makes.

Thanks everyone for the info