sulfer stank

I have recently changed my brewing setup (from insertion Chiller) so that my hot wort is pumped through a counterflow chiller before fermentation. I have meticulous sanitation practices and sanitize the chiller and pump with boiling water before and after each use.

Lately I have noticed my batches commonly off-gas a rotten egg odor. The offending yeasts include WL Check Budjevice and WL British Ale. Batches of WL Pilsner Lager and WL Belgian Ale produced in between those batches did not produce stank. My current theory is that my new setup has reduced the dissolved oxygen which has stressed the yeast and caused the stank.

Does this seam likely? Any sage advice?

Have you had any previous experience with the offending yeast? I'm not familiar with either type, but many yeasts will give off a sulphur odor. Its common with hefeweizen yeasts for example.

Yes I have used both yeasts many times w/ no problems.

I'm really not sure then. If your beers turn out fine, I wouldn't worry about it.

I've used the White Labs Czech Budejovice Lager Yeast yeast before and got a strong sulfur smell during fermentation, like a strong rotten egg smell. I used an immersion chiller and then pitched the yeast warm. After it got going, I cooled it to fermentation temperature. The smell disappeared after the lagering process for mine and left a very decent pilsner.

The sulfur smell is not uncommon for lager yeast from what I've read. I wouldn't worry about it. Just be sure to lager for a decent amount of time.

http://www.howtobrew.com/section1/chapter10.html

I used White Labs WLP023 Burton Ale and got a noticeable sulphur stench for about a day and a half, but it disappeared after that. It's fairly normal for some strains to occasionally give off that smell, although my understanding is that it is more common with lager and hefeweizen strains.