Does Starsan leave a residue in bottles?

I have an oatmeal stout conditioning right now and noticed a very slight film on the neck and part of the side of the bottle. The beer tastes and smells fine, although it's still green. If it's contamination, it's unlike anything I've seen before. I just started to try Starsan, and I'm curious if it could be Starsan residue. (The boil, cooling, fermentation, etc. went off without any problems at all.)

Until this batch, I've soaked my bottles in a bleach solution and then rinsed them with hot water right before filling. This time, I let them dry and then used a vinator to rinse them with Starsan. Most of the foam was purged when I filled the bottle, but some remained after it was capped. I'm wondering if what I'm seeing is the remnants of that foam? Have any of you seen anything like that? I'm not so much worried about the beer as I am curious about what I'm seeing.

Thanks!

It might be some leftover foam residue but do not fear the foam!!!!! It will be fine Iuse Starsan all the time for everything never an issue.

I should note it's actually the second time I used Starsan with bottles. The first time, I had to rinse. I then listed to the Basic Brewing Radio interview on it and lost my fear of the foam. As an experiment, I turned one bottle upside down several times and whatever I was seeing mixed into the beer. (It was almost like a thin strand of cobweb hanging from halfway up the headspace to the top of the beer.) We'll see if it comes back in a few days.

I'm planning on brewing a small batch this weekend. I think I'll use new yeast just to play it safe. When I bottle, I might rinse a handful of bottles and leave the foam in the rest to see if there is a difference.

Edit: Cobweb is a bad description. I looked again and it's more like an oil slick. If It gets on the side of the bottle, it clings to it and then moves with the beer if I jiggle the bottle. I searched old posts again and found this thread - sounds like what I'm seeing:

https://www.homebrewtalk.com/f11/star-san-oil-slick-145477/

I would have to say it is definitely NOT the Starsan. I use it all the top and ignore tons of foam... never saw a ring like that.

djnorberg said:

When I bottle, I might rinse a handful of bottles and leave the foam in the rest to see if there is a difference.

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Do NOT rinse Star San. Rinsing defeats the purpose of sanitizing.

logan3825 said:

Do NOT rinse Star San. Rinsing defeats the purpose of sanitizing.

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Right! - I'd only be rinsing a few as an experiment. I want to see if that is the source of the oil sheen I'm seeing. (Presuming it doesn't become something more obvious in the next few weeks!)

As far as I understand Star San breaks down into yeast food in the bottle. If you're seeing an "oil slick" type deposit then I would question your cleaning procedures from your bottles. The only thing I've observed in my Star San sanitized bottles is the yeast growing merrily on the bottom and carbonating my beer.

Star san won't turn solid into a 'cob web' either. I too think your bottle cleansing might need a re-visit.

If its not clean, you can't possibly make it sanitary.