Time to throw in the towel? Infected beer

[chewyheel]

I recently discovered my latest imperial stout was infected, most likely due to a stuck fermentation that I didn’t catch in time. Gravity was at 1.030, so I pitched more yeast to see if I could finish fermentation and maybe have a passable sour on my hands instead of dumping it straight away. However, it’s been about 36 hours since the yeast pitch and there appears to be no fermentation occurring. Time to give up on it? The Pic is currently what it looks like. Also if anyone has an idea as to what type of infection may have occurred I’d appreciate it.

 

[day_trippr]

Well, I'm not seeing an obvious pellicle here. Nothing that looks like colonies or rays or ice bergs.
What was in the original recipe? Could that film be oils from some addition - like coffee?

Cheers!

 

[Kerrbrewer]

Did it fail a taste test having an obvious flaw?

 

[Transamguy77]

I don't think you have an issue, and having a stuck fermentation won't cause an infection some alcohol has been produced. Now a long delay in fermentation can cause an infection but not a stuck one.

Taste it and see how it tastes, what was the OG? And how many unfermentables? It just might be done.

 

[divrack]

In this case my guess is that is the beginning of an infection but that's not necessarily a bad thing. It will take the gravity down if it's some kind of Brett, just slowly. It might just be the makings of your beer. Just keep as much o2 off it as possible and leave it for a while. If it starts to smell or taste solventy or acrid and harsh then chuck it and soak everything in cleaner followed by straight bleach followed by straight starsan rubs. Those plastic buckets can be a nightmare for nasties.
But on the plus side I've had an infection that I repropagated as it was delicious

 

[kingmatt]

No harm in letting it ride at this point to see what you end up with. You will need to buy a new fermenter anyway so you can start on a new batch.

 

[chewyheel]

Well, I'm not seeing an obvious pellicle here. Nothing that looks like colonies or rays or ice bergs.
What was in the original recipe? Could that film be oils from some addition - like coffee?

Cheers!

No special flavor additions, but lots of roasted and crystal malts though

 

[chewyheel]

I don't think you have an issue, and having a stuck fermentation won't cause an infection some alcohol has been produced. Now a long delay in fermentation can cause an infection but not a stuck one.

Taste it and see how it tastes, what was the OG? And how many unfermentables? It just might be done.

Haven’t actually tasted it yet, reckon I should do that though. OG was about 1.080 with lots of roasted and crystal malt. I’ve made this same recipe before and it finished at about 1.016

 

[keepcalmandbrewon]

You could try warming it up a few degrees, maybe it got too cold for the yeast? Also maybe give it a gentle swirl to try to rouse the yeast off the bottom and back up into suspension.

Edit, also if it's sitting at 1.03 I wouldn't be surprised if there was little to no karusen or visible signs of fermentation. Have you taken another reading this 36 hours post pitching another batch of yeast to see if it is still at 1.03?

 

[chewyheel]

Something I forgot to mention before was that when I originally discovered this issue the beer was in another carboy, and there was a much more noticeable layer of mold/gunk sitting on top of the beer, this was after a month sitting in the original carbooy. When I saw it I immediately transferred to a different one.

I just tasted it and it seems fine, nothing jumps out as obviously flawed, but the gravity still hasn't changed since I pitched the new yeast. I just gave it a stir so we'll see what happens, thanks for all the feedback.

 

[RM-MN]

Something I forgot to mention before was that when I originally discovered this issue the beer was in another carboy, and there was a much more noticeable layer of mold/gunk sitting on top of the beer, this was after a month sitting in the original carbooy. When I saw it I immediately transferred to a different one.

I just tasted it and it seems fine, nothing jumps out as obviously flawed, but the gravity still hasn't changed since I pitched the new yeast. I just gave it a stir so we'll see what happens, thanks for all the feedback.

Unless you fermented without an airlock or your airlock ran dry, you probably didn't have mold on your beer.

"Mold spores are everywhere, and they grow on any organic surface, given the right conditions. For growth, they require organic matter for food, moisture, warmth, and oxygen. "

Note that mold requires oxygen and in your primary fermenter there should be none. Once you move it to secondary you do have oxygen present and this can allow the growth of certain bacteria (note that I didn't say mold) which is one reason many of us recommend using primary fermenter only.

What you probably saw in your primary fermenter was yeast rafts brought to the surface by the escaping CO2.

Haven’t actually tasted it yet, reckon I should do that though. OG was about 1.080 with lots of roasted and crystal malt. I’ve made this same recipe before and it finished at about 1.016

With lots of Crystal malts and that high OG your beer is probably done at 1.030 and no yeast addition will change that. Give it a few more days to see if there is any change in gravity and if not, bottle that up.

 

[chewyheel]

Unless you fermented without an airlock or your airlock ran dry, you probably didn't have mold on your beer.

"Mold spores are everywhere, and they grow on any organic surface, given the right conditions. For growth, they require organic matter for food, moisture, warmth, and oxygen. "

Note that mold requires oxygen and in your primary fermenter there should be none. Once you move it to secondary you do have oxygen present and this can allow the growth of certain bacteria (note that I didn't say mold) which is one reason many of us recommend using primary fermenter only.

What you probably saw in your primary fermenter was yeast rafts brought to the surface by the escaping CO2.



With lots of Crystal malts and that high OG your beer is probably done at 1.030 and no yeast addition will change that. Give it a few more days to see if there is any change in gravity and if not, bottle that up.

Thanks for the insight, gravity is still the same so I think I’ll bottle soon.

 

[Saboral]

Thanks for the insight, gravity is still the same so I think I’ll bottle soon.

I’d be very careful, I’d let her go a little longer perhaps in a secondary to ensure fermentation is complete. At a 1.030 I’d be really worried it might continue to ferment after consuming your priming sugar and you’ll end up with over pressurized bottle that could burst.

Have you tried warming it first to get the yeast to come out of dormancy?