Film in Bottom of Keg

[im322305]

Hey all. I made three different 5-gallon batches of the same imperial stout recipe in order to fill a 10-gallon used bourbon barrel. Transferred to barrel yesterday. This morning when I was cleaning out one of the kegs I used to age one of the batches I found a film like substance on the bottom of the keg. This wasn't your typical yeast sediment at the bottom of the keg. I washed it out of the keg and put it on a paper towel (pic below). It's stringy, dense and in no way feels like yeast. Pics probably don't do it justice cause it's dried up a bit. I even tasted it and just tastes like the beer. Anybody ever seen this before in a keg of theirs? Seems like it was floating on the top of the beer because it caused the keg to clog at the very end of transfer. The beer that was in the keg tasted great, was sitting in keg for 5 months & was 12% ABV (complete beer specs below). Makes me think less likely infection but is cause for concern. Maybe coagulation of protein from a large % of oats I used and such? I dont know. The two other kegs that I used to age the other batches just had the normal yeast sediment as you'd normally see at the bottom of the kegs. Little I can do now but just wait and see. What are people's opinion of this and has anyone seen this in their beers before?

OG = 1.124
FG = 1.036
ABV = 11.8%
pH = 4.82

 

[RPh_Guy]

Could be:

1. Pellicle (from wild yeast contamination)
2. Some kind of residue if the keg wasn't cleaned properly
3. Some kind of coagulation from ingredients

That's the order of what I suspect it might be. Could you post the full recipe, including all the grains and other ingredients?

 

[im322305]

46% - 2 Row
16% - DME
12% - Malted Oats
5.5% - Munich
5% - Pale Chocolate
5% - Chocolate Rye
5% - Double Roasted Crystal
2.5% - Chocolate
2.5% - C-75
1.5% - Roasted Barley

Herkules & Simcoe @ 60 --> 70 IBUs
Imperial Yeast A07 pitched @ 1.50 mil/ml/Plato

 

[RPh_Guy]

I'm fairly certain none of those ingredients would cause anything like your photos.

If you're 100% certain the keg was clean, then it's a pellicle.

 

[im322305]

Yeah pretty sure your right. Keg was PBW'd overnight, rinsed multiple times, soaked in boiling hot water and then StarSan'd. With it accounting for 1/3 or less of the volume in the barrel what are the chances I'll have to dump it? Was going to bottle it and hand it out to people but pretty sure that might be out the window at this point.

 

[RPh_Guy]

It's unlikely you'll need to dump it, but I couldn't really say for sure whether it's safe to bottle and gift in the near future. You can't precisely track fermentation while it's barrel aging because water and/or ethanol will evaporate through the wood.

I generally don't recommend aging accidentally-contaminated beers, but at this point it's already old and going into a barrel so concerns about oxidation are moot. So I'd say just let it go. The longer you age it, the less likely there will be problems after bottling.

 

[beernutz]

In Bottom of Keg would be a good name for a film. Dibs.

 

[coonmanx]

Pretty sure I wouldn't worry about it too much. You made a dark beer and there is some dark residue.

 

[IslandLizard]

Pretty sure I wouldn't worry about it too much. You made a dark beer and there is some dark residue.

That's what I'm thinking too.

I have had sticky yeasty/trubby cakes deposits form in the bottom of kegs while in the keezer. Never noticed during dispensing, until some sludge comes out when it kicks. Especially with wheat and other "higher protein" beers. Now they weren't stringy/slimy/ropy as in Pedio cultures.