Sour Smell!

[CWR]

Hey Guys,

I know this is a typical noob thread, but I wasn't sure where to turn!

I brewed a Northern English Brown Ale on Sunday (Recipe Below). BIAB. Mashed @ 150 for 90 minutes. Boiled for 90 minutes. Ended up with 4.5 gallons of 1.041 wort.

Pitched with one packet of S-04. About 6 hours after pitching, fermentation was rocking. Things seemed to be going "okay," but then I smelled what was coming out of the airlock. It smelled bitter/burnt and slightly sour. I didn't think much of it, until this morning when fermentation seemed to stop. I roused the yeast, and left it for the day.

When I came home tonight, the fermentation was still stopped. I pulled the lid, and pulled a sample to test gravity. It's sitting at 1.02, and smells/tastes sour.

Soooooo...WTF? I've never experienced anything like this before. I've been telling myself all day RDWDAHB, but I can't help but think something is amiss.

Thoughts would be greatly appreciated!

----------
Grain Bill
8 lbs. - Maris Otter
1/4 lb. - Biscuit Malt

1/4 lb. - Chocolate Malt

1/4 lb. - Special B Malt

1/4 lb. - Special Roast Malt
1/4 lb. – Flaked Oats

Hop Schedule (27 IBU)
2 oz - Challenger (60 Min.)

1 oz - Fuggles (1 Min.)

Yeast
Safale S04 Dried yeast

 

[DCMayhem]

It's probably a lacto infection. I'm having a similar problem and the only thing I can determine is that it is lacto or some wild yeast that got in the beer. Did you do anything different to sanitize this time? Older equipment?

 

[CWR]

Thanks for the reply...this one caught me off gaurd...

My sanitation is typically pretty solid. I use starsan like it's going out of style.

In terms of my equiptment...My boil kettle is new, and meticulously clean. I run boiling wort through my ball valve assembly prior to chilling to sanitize the tube I use to transfer. I boil my IC for 10 minutes prior to chilling. etc.

The only difference with this batch is that I used some "saved" starsan from the previous days brew session on my fermenting bucket. I have done this before with no issue, but I wonder if I screwed this one up (Maybe it was a little weak when I mixed it, PH dropped, etc.)

Eek!!! I am going to give this a full week, then toss if it doesn't improve. I guess all will be well though, I think this recipe had too much special roast to begin with! :cross:

 

[theredben]

There is absolutely no reason to suspect Lactobacillus sp. infection at this point. Are you used to the taste of young beer yet? There should be no "sour" smell and I think that was pointing your tastebuds to a misdiagnosed taste. Most young beer contains a fair amound of acetaldehyde which some people describe as "green apple". Leave it in the fermenter for a few more weeks, bottle condition for 3 more weeks and then report back with your results.

EDIT: Can you post pictures of the inside of the fermenter? Assuming there is an infection there should be some kind of scum on top of the beer.

 

[CWR]

Well, it's been a week - and things are looking/smelling/tasting much better. I think my initial concern can be chalked up to the relatively high percentage of special roast malt in my grain bill. Reading other forums, and the Briess website, many have refered to the "sourdough" taste/aroma that this malt imparts. A week later (with an F.G. @ 1.013) the sour/burnt qualities are fading, and the hops are coming though on the palate. The aroma is still not there, so I might dry hop a bit - well see!

 

[theredben]

Always let the beer finish the fermentation. It is amazing how disgusting the beer can be mid-fermentation.

 

[jyda]

Always let the beer finish the fermentation. It is amazing how disgusting the beer can be mid-fermentation.

This is the first advice I've given to all my buddies that start brewing. Fermentation can seem like a nasty, smelly, messy process, but let it do it's thing and you'll end up with beer.