Oil slick on beer.

[shotataduck]

So this is has happened with every beer I've brewed. (I've only done 4 batches and I have sanitized all the carboys and equipment when siphoning). I can best describe it as a little oil slick that develops on the top. I didn't dry hop so shouldn't be hop oil. This developed in the secondary. It's been in the fridge for almost 3 weeks with no change. Could this be a residue left over from the starsan or is it Lacto? Is my beer screwed?

 

[shotataduck]

https://www.dropbox.com/s/41nzh7owllpq3pu/beerslick.JPG

Link to pic

 

[TopherM]

It's definitely not starsan. That looks like pretty typical lipids/fats, but I doubt you've put something fatty in all of your beers.

Residual cleaner, like PBW or Oxyclean, would explain it. Are you possibly not rinsing your cleaner adequately?