[PORTERHAUS]

Below are 2 pics of the surface of a finished beer I kegged lastnight. More than a few time I have seen this "film" on the surface. It seems quite mild, Its not on every batch but I have noticed it several times before. It doesnt seem to affect the beer, as far as I can tell. I have looked at pics of infections and pellicle? It doesnt seem to match exactly that. Its not thick, its not fury, or spongy, its not ropey, its not stringy. Its just a surface film that I havent been able to identify. 

The only thing tbat comes to mind is Starsan. Can this be risidual starsan, especially since I prepare my starsan with tap water and it does get cloudy and slimmy if left out.  This particular batch is an all grain Oatmeal Stout and I added cocoa nibs after primary fermentation.  1.055 OG, 5.4 mash ph everything went well on brew day. Beer cleared well, tastes fine, smells great. I mention starsan because as soon as I added my auto siphon (which had been soaking in starsan and was still went) to the carboy the film seemed to dissappear...or could have just been coincidence.

[natebrews]

If I had to guess (and I do) I would say that it is just oils from the beer that are sitting on the surface, maybe from the oats or the nibs.  I have seen similar "sheens" on the top of some of the beers I have made, never seemed to be a problem but it was definitely there.

[brewinhard]

Yeah, it does look like hop oils or along those lines.

[GS]

I agree. It doesn't look like a colony of  anything. Just an oil slick. You're good.

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[Bob357]

It could also be silicate residue from Fermcap-S if you use that. I\

[PORTERHAUS]

Thank you for taking a look guys. I have it kegged and carbonating waiting to try it out. Im going to pay closer attention to see when and what kind of batches I have this happen with.