Beer Forum

Hi folks, I've got a contaminated sweet chocolate stout on my hands, and I'm wondering what others would recommend doing with it at this point. I brewed it on the 14th of February this year, and added roasted cacao nibs and alcohol-soaked vanilla beans on the 26th. The white pellicle grew shortly after that so I blame one of those for the contamination, or maybe the hop bag I put them in. I've brewed 69 batches (dude), and this is the only one that's gone south so I think my sanitation is generally ok.

The beer has now been sitting for 6 weeks at around 13C/55F, and the gravity has not changed at all. It's a steady 1.016 - a bit higher than my usual stouts due to lactose in the recipe. It tastes ok. Not as sweet or chocolatey as I had hoped but drinkable enough, and it doesn't seem to be changing a great deal (yet).

Do you think it's safe to bottle? I don't know what's growing on it, but I don't want to end up with bottle bombs if it's something that can consume lactose in the long run. People often recommend leaving these things a year, but if the gravity is not changing is there any point?

Here is a photo taken through the Better Bottle if anyone wants to take a guess at what the white stuff is:

yep, thats a dumper alright.

snowcapt wrote:yep, thats a dumper alright.

It may come to that but I'm not keen to dump it while it still tastes ok! Last resort.

Looks to me like an acetobacter or brett infection. Any taste/smell of vinegar notes at all? Might be hard to detect in such a dark chocolate stout at this early stage. I would not package it, as it will most likely contaminate all of your other brewing equipment as well for future uses.

If you don't have the roomor equipment to let this sit for 8-12 months I would just dump it and start over

If you do have space and equipment I would just leave it and see what you get could be amazing!

That picture makes me want to go to your house and dump it for you. At first, I thought the picture was taken by a microscope.

I wonder what all that red stuff floating around is?

brewinhard wrote:Looks to me like an acetobacter or brett infection. Any taste/smell of vinegar notes at all? Might be hard to detect in such a dark chocolate stout at this early stage.

Yeah, it's really hard to tell. I've been pulling out a sample every couple of weeks and don't believe the taste has changed much. It's gotten a bit more bitter since I added the cacao nibs but I don't detect any vinegar - not yet anyway.

TheDarkSide wrote:I wonder what all that red stuff floating around is?

I think that's just small bits of roasted nibs that have escaped the hop bag. It's not a microscope but the picture is a real close-up.

I was hoping the fact that the gravity is stable would indicate something different, but it sounds like this is the usual wait and hope for the best scenario. I can't control the temperature without tying up my fermenting fridge but I do have the space to leave it be as is. Maybe that is the way to go.

Appreciate the feedback all.

Maybe you just invented a Sweet 'n' Sour Stout and it's the best beer you ever had. Good luck reproducing it.