Film in Primary

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brewNYC

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Hello, working on my 10th batch of beer and found something new. I have a thin, oily film in my fermenter that will not drop after 2 weeks. I suspect an infection because (a) the airlock is still slowly bubbling and (b) because I topped off with non-boiled bottled water (Great idea I got off another forum- I have since found that bottled water is not necessarily sanitary). However, the stuff on top looks more like yeast than pellicle or lacto. as you can see from the recipie below, there are a number of things that could have oil in them, including coffee and cocoa. What’s your opinion - infection, or just oily, yeasty scum?

OG= 1.056
FG= 1.018

Recipe (3-gallon batch)
3.3 lbs Dark LME (60 min)
8 oz dark DME (15 min)
4 oz lactose (15 min)
4 oz light roasted barley (mash @ 168)
4 oz chocolate malt(mash)
4 oz caramel 60L (mash)
8 oz cocoa powder (15 min)
2 cups course ground coffee (steeped in boil 15 min)
.5 oz cascade (60 min)
.2 oz cascade (15 min)

I usually chill this to 60 degrees, pitch SF-O5, then slowly let the temp rise to 68 over a week, then raise to 75 for 2 weeks, cold crash and bottle.

The hydrometer reading above was taken at 2 weeks, so I still have 1 week to go before I bottle. The hydrometer sample smelled a little fruity, but not vinigary. I didn’t notice an off-taste, but you could probably dump a pint of vinigar in this brew and not taste it, with all the dark malt, chocolate and coffee!

I plan to give this batch away (I can’t drink it, cause I’m lactose intolerant, but my wife and friends love this recipe). It woud be nice not to give away a bunch of infected brews!
 
The white stuff at the top of the fermenter looks like yeast to me. I can't see any oily films in the picture, so I can't help you there. It could be hops oils. Could you upload a better pic?
 
Nothing in the picture looks out of the ordinary to me. The stuff on the side of the carboy is yeast as tgolanos stated.

I think you're ok as nothing looks out of the ordinary in the picture, but if you can get a more clear pic, that might help.
 
Thanks guys, here is a picture through the top of the carboy. Any idea why this stuff won’t drop and why I’m still getting bubbles after 2 weeks?
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That looks fine. I don't believe you have any issues there.

As far as why it's not dropping and why you're bubbling, I don't have an answer for that but it's not really out of the ordinary. I've had a few where some of the stuff on top wouldn't drop. As far as the bubbling, it's not out of the ordinary. If the beer is changing temps a bit it could be offgassing some of the CO2 from the yeast.

As everyone always says, airlock activity doesn't tell you a whole lot. Only gravity readings will.
 
+1 what @Rob2010SS said.
Looks normal. The continued bubbling is off-gassing since the beer it's saturated with CO2 from fermentation. Warming the beer accelerates this.

Cheers
 
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