Coopers stout - probable infection

[hathro]

Hi guys,

I've put on a coopers stout that's been fermenting for 7 days. Two things I'm worried about, the FG is high, it's stopped fermenting (same SG over the last 2 days) and it tastes sour!

Some info:
Coopers stout can
Yeast that came in the can
Brew enchancer 1
OG 1.046
FG 1.018
23L brew

Thought I'd check here first. A bit annoyed as I'm religious with cleaning and sanitising but these things happen. As this is the first time it's happened, thought I'd check here for some advice before dumping it and starting again!

If the advice is to dump it, please chuck up an extract stout recipie for me to follow. I'd like to experiment a bit more than just following the can instructions.

Cheers in advance.

 

[mosto]

Is 1.018 what it is currently, or what you expect the FG to get down to? If the latter, what is the current gravity? What temp has it been sitting at? Does the krausen look that same as previous brews?

Sorry, lot of questions, but just trying to better understand what's going on inside that fermenter.

 

[blackbeard2]

If the advice is to dump it, please chuck up an extract stout recipie for me to follow. I'd like to experiment a bit more than just following the can instructions.

I couldn't say for certain wether or not you should be dumping at this stage - thankfully I don't have any experience with an infected batch yet.

However on the topic of an extract stout recipie - I thought I'd chime in and direct you towards this one from the database which I'm planning on putting down very soon:

http://aussiehomebrewer.com/recipe/914-coopers-best-extra-stout-clone/

Haven't made it yet - but I was using Ianh's spreadsheet trying to plan a kit + bit stout recipe and they all seemed to come out with too many EBC's for the style once you added any additional extract or spec grains. This one looks good style wise and sounds like it will be exactly what I was hoping for (something very close to coopers commercial stout)

I'll cross my fingers that your batch is still okay though!

 

[hathro]

Is 1.018 what it is currently, or what you expect the FG to get down to? If the latter, what is the current gravity? What temp has it been sitting at? Does the krausen look that same as previous brews?

Sorry, lot of questions, but just trying to better understand what's going on inside that fermenter.

Hi mosto, no problems.

1.018 is what it is currently at and has been for 2 days.

It has been sitting at 23/24 degrees.

The krausen was larger (higher in the fermenter) than previous brews but looked great - my previous brews have been coopers pale ales. The krausen has now completely disappeard.

 

[hathro]

However on the topic of an extract stout recipie - I thought I'd chime in and direct you towards this one from the database which I'm planning on putting down very soon:

http://aussiehomebrewer.com/recipe/914-coopers-best-extra-stout-clone/

I'll cross my fingers that your batch is still okay though!

Thanks for the info blackbeard2! Much appreciated.

 

[mosto]

Hi mosto, no problems.

1.018 is what it is currently at and has been for 2 days.

It has been sitting at 23/24 degrees.

The krausen was larger (higher in the fermenter) than previous brews but looked great - my previous brews have been coopers pale ales. The krausen has now completely disappeard.

I don't think I'd be dumping it just yet mate. According to ianh's spreadsheet, it should finish around 1.012, so it's not far off. Maybe pick the fermenter up and give it gentle swirl to try and get the yeast back on the job. At a stretch stick a sanitized spoon in and give it a stir, but that would be a last resort as it's not best practice to go opening up the fermenter and sticking things in there.

Apart from the sour taste everything else seems ok, but it's hard to tell what that may be coming from. Some brews don't taste all that special during fermentation.

So try a swirl to kick start the yeast and get it down to under 1.015 at least. If bottling, and it doesn't quite reach 1.012, maybe under prime a little to allow for any unfermented sugars that may be in there. Stout's are only lightly carbed anyway so shouldn't hurt the beer if a little under carbed.

 

[hathro]

Thanks motso.

I put a sanitised spoon in there last night and stirred things up. Half cracked the lid, quick stir then down.

I'll take your advice and leave it for a few more days and see what happens to the SG. After that, I'll bottle and under prime - this makes a lot of sense. Might have to use sugar instead of carbonation drops this time.

 

[mosto]

Should have added, if you do bottle with the FG a little high (as I said, I'd like to see it under 1.015) use PET bottles. That way you can give them a squeeze to see if they're getting too hard. If they are, twist the caps enough to let some pressure out and re-tighten.

 

[hathro]

It's down to 1.016 now. Will check again tomorrow.

If it is under 1.015, is it okay to use glass bottles or use PET just to be safe?

 

[NewtownClown]

if you harbour any doubt, bottle in PET, if even just for peace of mind. If you do have a lacto- or aceto- infection it may continue to ferment further. BTW even PET's can explode.

Is the "sour" taste vinegarish or sour milk/yoghurt like?

 

[hathro]

Just tasted it then. Tastes more "green" than sour now. I can taste the stout flavour.

I would say vinegar. Made me screw my face up when I tasted it and couldn't taste any of the beer/stout flavour. It was more like when you have lemon rather than rank milk/yoghurt.

 

[manticle]

Any suspicious looking white growth on top?

Might just be green beer and green brewer. In which case, all good.

 

[hathro]

No white growth. I'm going with green beer, green brewer.

Thanks for all the advice guys. You're a bunch of top blokes.

 

[hathro]

I bottled this into P.E.T on the 5th of Jan. Checked last night and the bottles were rock hard. Gave them a release and will monitor from here.

 

[mosto]

What was your FG?

 

[hathro]

FG was 1.016