Fermentation Issues

[kocken42]

Hey,

First of all, I put down my first AG BIAB the other day (21/09/10). It was poured onto about one quarter of the trub of the previous batch (clean Dr.Smurto's Golden Ale). Now, the beer has finished fermentation due to the fact that it rocketed after landing on the trub. During the ferment, it smelt fantastic, but now I am getting what I can only describe as burnt rubber, but it COULD be something else.

Anyway, I presume that putting wort on a trub (it was a 'fresh' trub so to speak) is perfectly fine so I doubt it is a smell due to autolysis and sitting on a reductive smelly trub for a few days. I am concerned that perhaps the wort was not oxygenated enough, which has led to the formation of disulphides.

Does anyone have advice or experience with this?

Is it just a case of RDWHAHB and the yeast will clean it up in a few days?

Cheers.

Edit: It was a US-05 trub.

 

[keifer33]

How bizarre to read this and have nearly the same issue. Hadn't thought lack of aeration could be the cause. Was it us05?

 

[kocken42]

Yeah it was.

The smell is quite terrible, but there isn't any burnt rubber flavour or off flavours.

From what I can gather it is either:
1. Reductive odours due to yeast autolysis.
2. Formation of disulphides due to lack of aeration (again due to reductive (anaerobic) environment).
3. Lack of nutrient for yeast.

I have had this kind of smell occur in white wines (20'000L of it) and the remedy was to pump it over to get some oxygen into it, and if that failed to work, DAP (diammonium phosphate) would we added and the wine pumped over again. It was OK to do this becuase the wine was still fermenting and had enough dissolved CO2 to reduce the effects of oxidation.

If it doesn't disappear in a week or so it might have to be racked with a bit of 'splashing' and then consumed sooner rather than later.

 

[DKS]

Hey,

First of all, I put down my first AG BIAB the other day (21/09/10). It was poured onto about one quarter of the trub of the previous batch (clean Dr.Smurto's Golden Ale). Now, the beer has finished fermentation due to the fact that it rocketed after landing on the trub. During the ferment, it smelt fantastic, but now I am getting what I can only describe as burnt rubber, but it COULD be something else.

Anyway, I presume that putting wort on a trub (it was a 'fresh' trub so to speak) is perfectly fine so I doubt it is a smell due to autolysis and sitting on a reductive smelly trub for a few days. I am concerned that perhaps the wort was not oxygenated enough, which has led to the formation of disulphides.

Does anyone have advice or experience with this?

Is it just a case of RDWHAHB and the yeast will clean it up in a few days?

Cheers.

Edit: It was a US-05 trub.

Guys, I had that horrible burnt rubber in a brew recently and nearly tossed it out. After a month in the bottle it started to lessen ,at six weeks less still, at eight weeks all but gone.
Same yeast, us-o5, I think I pitched it a bit cold and may have shocked it and may have slightly under pitched, it was also 4th gen.

I have no technical advice just my recent experience.
The reading I did, suggests yeast health or lack of, is the main cause. So don't toss it give it some time it may come good. :icon_cheers:
Daz

Edit: The burnt rubber cant really be mistaken for anything else and everyone said "you'll know when you get it" and I did.

 

[kevin_smevin]

Guys, I had that horrible burnt rubber in a brew recently and nearly tossed it out. After a month in the bottle it started to lessen ,at six weeks less still, at eight weeks all but gone.
Same yeast, us-o5, I think I pitched it a bit cold and may have shocked it and may have slightly under pitched, it was also 4th gen.

I have no technical advice just my recent experience.
The reading I did, suggests yeast health or lack of, is the main cause. So don't toss it give it some time it may come good. :icon_cheers:
Daz

Edit: The burnt rubber cant really be mistaken for anything else and everyone said "you'll know when you get it" and I did.

Was reading a bit of how to brew the other day and it said the burnt rubber was due to yeast autolysis. Check it out http://www.howtobrew.com/section1/chapter10-3.html. Could of course be something else.

 

[Shed101]

Same again, I can't offer any advice, just my experience.

I had a 3rd or 4th gen. US-05 develop a nasty flavour ... after having some wacky esters in fermentation at 18C. I put it down to under-pitching.

I thought it was fusel, and had totally written it off, but after six weeks it's come good.

It's almost like getting given some free beer :lol:

 

[rclemmett]

I pitched directly onto a yeast cake once, and I have never done it again. I can't quite remeber if it had a burnt rubbery smell but I do remember it being a little like vegemite. I put the smell and taste down to Autolysis...

When you pitch directly onto the yeast cake it is likely to ferment out very quickly, and in doing so generate some pretty high temperatures, even in a temp controlled fridge.

 

[kocken42]

Autolysis takes a significant amount of time to become noticeable, and pitching onto yeast trubs shouldn't be an issue. It's what a lot of micro-breweries do.

The temp maxed out at 22 deg C.

There was no adjuncts in the brew so nutrients from the malted barley should be sufficient for yeast health.

I'm going to say under-pitching (although about 2 cups of trub should be PLENTY!) or lack of aeration.

 

[rclemmett]

Autolysis takes a significant amount of time to become noticeable, and pitching onto yeast trubs shouldn't be an issue. It's what a lot of micro-breweries do.

The temp maxed out at 22 deg C.

There was no adjuncts in the brew so nutrients from the malted barley should be sufficient for yeast health.

I'm going to say under-pitching (although about 2 cups of trub should be PLENTY!) or lack of aeration.

If it was finished in 3 days under pitching seems unlikely to me...

 

[DKS]

If it was finished in 3 days under pitching seems unlikely to me...

Yes I agree Rob. Temp maybe, if its going that fast and a temp probe is not in the brew but only in the fridge that maybe a prob.
Finished in three days? I think a re-evaluation of the problem. I'll have a beer and think about it.That said that wasn't my prob as previously posted :icon_cheers:
Daz