What is that smell?

[Cptn_Needa]

I've just dry hopped my second ever AG brew (have done plenty of kits over the years) and noticed a spectacular whiff when I opened the FV to check the SG hadn't moved over two days and add hops.
I'm not great at identifying aromas but my wife (who is sometimes better) said it smelled like rotting/fermenting fruit. I can only place it as "unpleasant".
Once out of the FV the beer smells like beer and tastes mostly like beer although it does have a slight taste of whatever "it" is but it's pretty subtle.

Chief suspect is the S-04 yeast. I've read from a few people that they have detected slightly off flavours using this yeast, though others do not detect anything unusual.
The other possibility I thought of is the Maris Otter which I have had for a few years but has been stored unopened in a cool dark cupboard.

The recipe I made was:
3000g Maris Otter Pale (this was past its BB date by a year but had been stored cool and dark)
300g Crisp Clear Choice Extra Pale
100g Crisp Cara
60 minute mash @ 67degC
60 minute boil
12g Magnum Leaf (60) 16.5 IBU
10g Perle pellets (60) 6.4 IBU
12g Cascade leaf (30) 11.3 IBU
1 tspn Irish Moss (15)
12g Cascade Leaf (0)

11.5g S-04 (starter made 36hrs before pitching using 60g beer enhancer, 600ml water and 1 nutrient capsule)
Pitched @ 23degC (to match starter temp)
FV volume 18.5l @ 1.041
Fermented for 14 days @ 20degC (temp controlled brew fridge)
FG 1.006 (which is lower than the target of 1.010 in the recipe)
Beer is clear and floculation(?) was good (big clumps)

Anyone got any thoughts?
It's getting bottled and drunk regardless

 

[JockyBrewer]

Probably just a bit of yeast that's dried out, particularly if said yeast has then dropped back into the beer. Over time it will drop out and go away.

 

[Cptn_Needa]

Probably just a bit of yeast that's dried out, particularly if said yeast has then dropped back into the beer. Over time it will drop out and go away.

Thanks @JockyBrewer
Is that pretty common?
I've never smelled anything like it from a brew previously

 

[Linalmeemow]

The smell will probably go away, you do tend to get some odd aromas during fermentation.

No need to make a starter from dry S04 for a beer of this size though, just adds another potential source of infection. Also, most advice is not to make a starter from dried yeast at all.

 

[An Ankoù]

It's unlikely to be the Maris Otter or any of your ingredients. Sometimes the fermentation stinks and sometimes the smell disappears in conditioning and sometimes it doesn't. I've come to the conclusion that it's something to do with the fermentation itself, either the yeast is stressed or it's a bit too warm or there isn't enough nutrient. I had a spate of it with different yeasts, including S-O4 earlier in the year and decided to improve my cleaning regime by putting dilute bleach in my fermenters for 24 hours before putting them away with a couple if inches sodium metabisulphite solution inside to kill the chlorine and keep them sweet. I didn't get the problem again, but then I also changed my yeasts from ale yeasts to warm-weather yeasts and kveiks. With one exception- Lallemand ESB is an absolute stinker and the beer I made is still tainted after 4 or 5 months. I'll probably chuck it.

 

[Cptn_Needa]

The smell will probably go away, you do tend to get some odd aromas during fermentation.

No need to make a starter from dry S04 for a beer of this size though, just adds another potential source of infection. Also, most advice is not to make a starter from dried yeast at all.

Thanks Linalmeemow
Made a starter following a recommendation to get the fermentation kick started. It did a job. Maybe next time I'll just re-hydrate.

 

[Cptn_Needa]

It's unlikely to be the Maris Otter or any of your ingredients. Sometimes the fermentation stinks and sometimes the smell disappears in conditioning and sometimes it doesn't. I've come to the conclusion that it's something to do with the fermentation itself, either the yeast is stressed or it's a bit too warm or there isn't enough nutrient. I had a spate of it with different yeasts, including S-O4 earlier in the year and decided to improve my cleaning regime by putting dilute bleach in my fermenters for 24 hours before putting them away with a couple if inches sodium metabisulphite solution inside to kill the chlorine and keep them sweet. I didn't get the problem again, but then I also changed my yeasts from ale yeasts to warm-weather yeasts and kveiks. With one exception- Lallemand ESB is an absolute stinker and the beer I made is still tainted after 4 or 5 months. I'll probably chuck it.

Cheers An Ankoù
I'll give the FV a proper good clean when it's done. Always good practice. I've only got VWP and Star San for my cleaning/sterilising/sanitising at the moment so will give it a good soak in VWP and then a good rinse out after. I'll see if my local shop has any sodium metabisulphite.
Next round of brew is using S-04 again so hopefully a good clean will keep the whiff down and the current batch will reduce in conditioning.

 

[An Ankoù]

Cheers An Ankoù
I'll give the FV a proper good clean when it's done. Always good practice. I've only got VWP and Star San for my cleaning/sterilising/sanitising at the moment so will give it a good soak in VWP and then a good rinse out after. I'll see if my local shop has any sodium metabisulphite.
Next round of brew is using S-04 again so hopefully a good clean will keep the whiff down and the current batch will reduce in conditioning.

I'm pretty sure VWP is a chlorine (ie bleach) based cleaner so that's good. The metabisulphite, as well as being a sanitiser in itself, will remove any last traces of chlorine left over from the VWP. I don't think Starsan does that.
I've had some success in reducing the whiff by adding a teaspoonful of yeast nutrient. It seemsed to work, but might have just been coincidence.

 

[Cptn_Needa]

I'm pretty sure VWP is a chlorine (ie bleach) based cleaner so that's good.

It certainly smells like one and has the same effect as bleach when I splash it in my t-shirts

I've had some success in reducing the whiff by adding a teaspoonful of yeast nutrient. It seemsed to work, but might have just been coincidence.

I did add nutrient to this brew. It was a servomyces yeast nutrient capsule which I opened and poured the contents in the starter. Maybe it did reduce it and I actually got a toned down version

 

[JockyBrewer]

Thanks @JockyBrewer
Is that pretty common?
I've never smelled anything like it from a brew previously

Not really that common, but I've had something similarly weird (and it might have been S-04 thinking about it...) where yeast dried up on around the top of the fermenter, then fell back in to the beer.

The other possibility is an infection or oxidation. Without tasting your beer it's impossible to say.

 

[Cptn_Needa]

Not really that common, but I've had something similarly weird (and it might have been S-04 thinking about it...) where yeast dried up on around the top of the fermenter, then fell back in to the beer.

The other possibility is an infection or oxidation. Without tasting your beer it's impossible to say.

I'll check out the crud around the top and see if any has dropped off when I bottle.
If it's an infection I think it's pretty low level (at the moment at least) as the taste is pretty much spot on. Guessing that may change over time
Oxidation would have to have come prior to pitching as it was left untouched with an airlock during fermentation. It is possible though as I don't have a wort chiller and had to cool down in a sink of cold water. It took many hours.

...Without tasting your beer it's impossible to say.

I'll send some over
This does kind of get to the issue I have on whether I'm doing it right and what I'm actually tasting though. I have seen this pdf but since I'm terrible at putting my finger on what the taste is, which makes diagnosis pretty tricky. I need a taster

 

[foxbat]

Once out of the FV the beer smells like beer and tastes mostly like beer although it does have a slight taste of whatever "it" is but it's pretty subtle.

If it smells like artificial butter, even rancid butter then it's diacetyl. S-04 reportedly does throw off quite a lot of the stuff which it then naturally cleans up at the end of fermentation.

 

[Cptn_Needa]

If it smells like artificial butter, even rancid butter then it's diacetyl. S-04 reportedly does throw off quite a lot of the stuff which it then naturally cleans up at the end of fermentation.

Fingers crossed it does a decent job or cleaning up after itself.
Cheers for the advice

 

[Lesinge]

I've just dry hopped my second ever AG brew (have done plenty of kits over the years) and noticed a spectacular whiff when I opened the FV to check the SG hadn't moved over two days and add hops.
I'm not great at identifying aromas but my wife (who is sometimes better) said it smelled like rotting/fermenting fruit. I can only place it as "unpleasant".
Once out of the FV the beer smells like beer and tastes mostly like beer although it does have a slight taste of whatever "it" is but it's pretty subtle.

Chief suspect is the S-04 yeast. I've read from a few people that they have detected slightly off flavours using this yeast, though others do not detect anything unusual.
The other possibility I thought of is the Maris Otter which I have had for a few years but has been stored unopened in a cool dark cupboard.

The recipe I made was:
3000g Maris Otter Pale (this was past its BB date by a year but had been stored cool and dark)
300g Crisp Clear Choice Extra Pale
100g Crisp Cara
60 minute mash @ 67degC
60 minute boil
12g Magnum Leaf (60) 16.5 IBU
10g Perle pellets (60) 6.4 IBU
12g Cascade leaf (30) 11.3 IBU
1 tspn Irish Moss (15)
12g Cascade Leaf (0)

11.5g S-04 (starter made 36hrs before pitching using 60g beer enhancer, 600ml water and 1 nutrient capsule)
Pitched @ 23degC (to match starter temp)
FV volume 18.5l @ 1.041
Fermented for 14 days @ 20degC (temp controlled brew fridge)
FG 1.006 (which is lower than the target of 1.010 in the recipe)
Beer is clear and floculation(?) was good (big clumps)

Anyone got any thoughts?
It's getting bottled and drunk regardless

I used a Mangrove Jacks West Coat yeast which was very lively and spilt over the top of my fermenter - the stink after a few days (I leave them to look after themselves for a week or so) was of fish - awful...beer was fine though!

 

[Cptn_Needa]

I used a Mangrove Jacks West Coat yeast which was very lively and spilt over the top of my fermenter - the stink after a few days (I leave them to look after themselves for a week or so) was of fish - awful...beer was fine though!

Good to know. That's on my list of yeasts to try on my next IPA.

 

[Pavros]

I'm pretty sure VWP is a chlorine (ie bleach) based cleaner so that's good.

VWP definitely is chlorine based as I have to be very careful using it due to my asthma.