Us-05 Smells Like A Fart

[Rodolphe01]

I've had a brew down for 9 days now, 19-20 degrees the whole time (in fridge w/ temp controller). I opened the fermenter to have a peek and it stinks like a fart, think lager yeast sulphur odour. From this brew I have decided to stop racking to secondary to reduce handling etc and had planned on leaving it in primary for 3 weeks then going straight to bottles, rather than a 1 week ferment and 2 weeks in secondary.

I've not noticed this odour before with US-05. I doubt it, but is yeast autolysis a possibility? Should I rack it off the yeast cake as I have done in the past? I have a spare fermenter so it isn't a huge drama, i'd just rather not

I've read a around here a bit about the apparent waste of time racking to secondary is hence the move the shy away from it.

Cheers.

 

[manticle]

It's not a waste of time if you notice a difference and have a good reason to do it. It is a waste of time if it's just done because you read somewhere that it can be done

I'm not sure if autolysis is vegemitey or sulphury or both. I have a concern with a recent red ale I put down - not my recipe and the instructions state specifically not to rack but it sat on the primary for around 3 weeks (cold conditioned once FG was reached for a bit over a week). Normally this wouldn't concern me but there was a hint of vegemite on tasting before bottling. I'll have to see how it goes.

How does it taste and is it just in the fridge or noticeable specifically from the fermenter (outside the fridge, sample vessel etc)?

 

[Screwtop]

I've had a brew down for 9 days now, 19-20 degrees the whole time (in fridge w/ temp controller). I opened the fermenter to have a peek and it stinks like a fart, think lager yeast sulphur odour. From this brew I have decided to stop racking to secondary to reduce handling etc and had planned on leaving it in primary for 3 weeks then going straight to bottles, rather than a 1 week ferment and 2 weeks in secondary.

I've not noticed this odour before with US-05. I doubt it, but is yeast autolysis a possibility? Should I rack it off the yeast cake as I have done in the past? I have a spare fermenter so it isn't a huge drama, i'd just rather not

I've read a around here a bit about the apparent waste of time racking to secondary is hence the move the shy away from it.

Cheers.

Did you pitch a rehydrated within date pack. Or...........................shiver...........pitch onto yeastcake or repitch?

Wouldn't have been long enough on the yeast for Autolysis I wouldn't think.

Screwy

 

[Kai]

It's not autolysis per se, but can be a sign of poor yeast health. US-05 will throw up sulphur during the ferment if it's a bit stressed, running cold, too much SO2 in the water and so on.

 

[schooey]

I doubt that it's autolysis after only nine days... and I struggle with the term 'vegemitey' with autolysis. In my experience, autolysis smells and tastes more like those red rubber stoppers, the ones you put in the top of a conical flask, getting too hot. But every nose is different

Also from my experience, the rotten egg/sulphur odours are more associated with lager yeasts. those same odours, although slighty different (even faecal) can be associated with wild yeast infections or other sanitation issues not neccessarily related directly to US-05

 

[Rodolphe01]

The yeast was salvaged from a previous brew, washed 3 times and capped, then in the fridge. This is the third of 5 that I have used from the same batch (none of the other were problematic) and it didn't smell funky from the bottle it was in - I pitched ~1/4 of a stubbies worth of slurry. Probably the poor yeast health thing Kai refers to, it is my understanding that re-used yeast cake can contain a large amount of yeast in poor health. I will rack it off anyway just because and see how it goes, I will taste it at this time too. Serves me right for being tight and recycling dry yeast however I am now set-up a wee bit better to split up liquid yeasts and was going to be doing this from now on anyways. Taste test will determine if it is infection I suppose.

 

[mckenry]

I had a similar problem.

here

 

[Screwtop]

The yeast was salvaged from a previous brew, washed 3 times and capped, then in the fridge. This is the third of 5 that I have used from the same batch (none of the other were problematic) and it didn't smell funky from the bottle it was in - I pitched ~1/4 of a stubbies worth of slurry. Probably the poor yeast health thing Kai refers to, it is my understanding that re-used yeast cake can contain a large amount of yeast in poor health. I will rack it off anyway just because and see how it goes, I will taste it at this time too. Serves me right for being tight and recycling dry yeast however I am now set-up a wee bit better to split up liquid yeasts and was going to be doing this from now on anyways. Taste test will determine if it is infection I suppose.

Had a thought that could be the case! Try to use good pitches of healthy yeast, dried yeast is cheap.

Screwy