Is my batch infected? (Pics)

[Microphobik]

So, i have been working on a troublesome chocolate milk stout for almost two months. The only trouble being that I haven't been able to get the gravity down low enough. The FG came in at 1.027 after accounting for what the lactose added, which actually brought I to 1.036. On the plus see it has tasted great all the way along. I have decided that I must not be getting an accurate temperature reading during mash and am probably just mashing a bit higher than I thought. A problem because I was trying to mash high to begin with for a big bodied beer.

At about the 30 day mark I tried racking to a secondary in case the problem was a stuck fermentation. I was wondering if I had oxygenated enough and figured the racking might kick things back into gear. Only issue was that there was a good 5 inches in the secondary after racking. But I did see the odd bubble the next day and assumed I was fine and that there was CO2 production taking place. Turns out that wasn't the problem because there has been no change in gravity.

The next day I had to leave town for three weeks. I came back to find a slightly concerning film on top of the beer. It was very mild, but it was almost oily and looked a bit like A Kham yeast formation like you might find on Sauerkraut. But it was so mild it was hard to tell. It also had a few bubbles which looked more like Krausen than a yeast growth but I wouldn't expect Krausen after 3 weeks in a secondary.

Keep in mind, this has cacao beens soaked in vodka in it, as well as lactose. And I soaked the cacoa for about two weeks and then left them in the primary for several weeks. That was longer than recipe called for and I may have pulled oil from the nibs.

I tasted it and found zero noticeable off flavors so I bottled. 3 days later I am seeing a similar film/ring at the surface line in the bottle.

The lack of off flavor had me thinking this might just be cacao oil and maybe activity triggered by me coming home after three weeks and cranking up the heat in the house. But the film appearing in the bottle has me thinking infection of some kind.

I've never had an infected batch nor have I ever made a milk stout or used cacao before so I don't know what to make of it. Would love a few educated opinions.

It's kind of hard to tell in the pics but take a look at what I'm talking about in the attached pics.

 

[eastoak]

Yes it is.

 

[Pratzie]

pellicle baby! add it to the pellicle thread!

 

[passedpawn]

Yep, infection.

The effect though is hard to guess. You might get gushers or some funk. With a dark beer, you might not notice anything.

 

[eastoak]

You say you racked to a secondary in case it was a stuck fermentation, that is the opposite of what you want to do for a stuck fermentation. Taking the beer off of the yeast will not make the gravity drop. An infection can come from any number of sources: your hands, mouth, clothing, a hose, the air, the list is endless. If the beer still tastes good to you then all is well, if not then it's time to decide what to do with it.

 

[Microphobik]

Bummer, after doing a bunch of of digging based on things everyone mentioned I'd say that this is definitely a lacto infection.

What is likely to happen at this stage? Will the lacto infection cause more CO2 production that expected and lead to exploding bottles, or am I just worrying about the souring effect it may, or may not have?

I have read so many different things about whether to dump or keep after a beer gets infected. What is everyone's opinion? I hate the idea of drinking anything that is "infected", but am I just reacting to the word and should I not worry about it as long as there are no off flavors? Just kind of wondering what others would do?

And will the CO2 production cause the infection to cease or will this keep on growing and changing in the bottles?

 

[monsterbrewerMa]

I just had the same thing in my choc milk stout with cocoa nibs and vanilla beans. I kegged it anyway, and two weeks later... its pretty darn good!

 

[monkeybox]

I have read so many different things about whether to dump or keep after a beer gets infected. What is everyone's opinion?

My favorite answer is this:

If you have a batch that doesn't come out well, put it in the back of the closet. Sample one bottle a month until one of two things happens: Either (A) it tastes good, or (B) you run out.

 

[Microphobik]

My favorite answer is this:

If you have a batch that doesn't come out well, put it in the back of the closet. Sample one bottle a month until one of two things happens: Either (A) it tastes good, or (B) you run out.

Good advice, thanks!

 

[daksin]

I don't know, the worry with infections is that you'll get something superattenuative and blow up your bottles. If the beer is carbonated and tastes good, GET IT COLD NOW and don't hesitate. That will greatly slow down the infection and let you enjoy the beer.

 

[Microphobik]

I don't know, the worry with infections is that you'll get something superattenuative and blow up your bottles. If the beer is carbonated and tastes good, GET IT COLD NOW and don't hesitate. That will greatly slow down the infection and let you enjoy the beer.

That also makes a lot of sense. Thanks.

 

[Microphobik]

Just thought I'd follow up for anyone who reads this who might have the same situation....

I bottled it 3 weeks ago and have had a few. No noticeable bad taste. Probably not the best beer I will ever make, but one I wouldn't complain about if I bought it at a pub either. I thought I caught a whiff of something in the first sip of one I had following a pale ale, but couldn't find the aroma/taste again.

No additional growth in bubbles beyond what you see in the pic and it pretty much disappears if you give the bottle a gentle shake. I'm guessing the C02 from carbing kept it at bay. No weird carb issues either. Carb levels are at anticipated levels.

Just thought I'd post the update, for what it;s worth.

 

[Hanso]

Yea keep it cold and go through it quickly. Probably replace your racking lines or take a careful look at you carboy/equipment to avoid for future batches.