Rotten egg smell from fermenter to keg

[nwbrewing32]

Hey Everyone,

I kegged an ESB that had some sulfur/rotten egg smell coming from it on day 12 of fermentation. Starting OG was 1.041 and I pitched a 1L starter of Wyeast 1469 West Yorkshire Ale yeast. When I purged the keg a few days later, it still had the smell.

I contacted a local home brew shop who recommended I scrub the beer by pushing CO2 through the long dip tube. I did this and it considerably reduced the smell, but each day when I purge I still get a little of the smell.

Tasting it, I cannot detect any flaws. And when I smell just a glass, can't really smell the sulfur either.

So, is this an infection? Or just sulfur trapped in the beer? I also ran another beer through the serving line. Do I need to sanitize or toss that? If it's an infection, I don't want it spreading to the other keg.

Thanks!

 

[Dcpcooks]

There are four yeast or malt specific compounds that produce sulfur smells in beer. Lager yeast produce a bit more and the lower fermentation temps slow fermentation down so they are not driven off as fast as an ale ferment might.

They should dissipate in time. You may want to let the beer sit longer on the yeast.

One potential concern is DMS or dimethyl sulfide a sulfur derivative . You may want to consider a more rigorous boil and insure you don't have a lid on during the boil. If you notice a cooked corn flavor that was the cause. DMSO is another off flavor precursor present in grain that is not effected by the strength of the boil.

Your best prevention for sulfur is a strong boil and a healthy and vigorous fermentation. Make sure your pitch is correct and you have the beer at the proper temp for fermentation.

 

[FVillatoro]

I have gotten only gotten heavy sulfur from WLP029 Kolsch yeast strain fermented cool.

What I did is that after fermentation was complete, I raised the temp of the beer slowly to 70 degrees to degas it and scrub off the sulfur, and held it there 4 days. After i removed the lid and smelled, the sulfur was gone completely.

As the above forum member posted, it could also be DSM if you didn't get a strong boil or took too long to cool it.