Oil Slick?

Recently brewed an Alaska Amber clone and after 2 weeks in primaryand 2 weeks in secondary it had iridescent swirls on top of the beer in the fermenter it is pretty high gravity over 8% ABV anyone know if this is normal or not? Sorry for the noobish question
Josh

Could be infection, try it and see if it smells or tastes off.

Failing that, is there any grease on any of your equipment?

Can esters or fuesel hot type alcohol cause these?

i thought it was from hop oils.

The only thing I can think of that creates an oily sheen ontop of beer would be the start of an acetobacter pectile. The good news is it will be very easy to tell IF this is the case by taste and smell if it has begun turning it into vinegar.

Smells fruity which I knows was from a hot fermentation because my temp controller didn't arrive in time...fail

I sometimes see this after I transfer to secondary (when I use one). I attribute it to the starsan foam residue. I mix starsan with my well water (I use RO water for brewing) and it's just hard and crappy. The beer always turns out fine though.

The only other time I see it is when I use corn adjuncts and that's just a small amount of corn oil.

I see this fairly regularly on mine, especially when I secondary. I always figured it was starsan like waldoar. Nothing to worry about in my experience.

Star San user here too...the more you know

Well, don't celebrate just yet. Just letting you know that there can be other reasons for that little oil slick looking sheen besides infection. If the FG keeps dropping or if the beer starts smelling of Vinegar or some such, you may be in trouble.

I seem to get this quite often on a lot of my beers (I only use a bucket for primary anywhere from 4-12 weeks [when I can get to transferring to keg]). Haven't had a problem yet *knock on wood*.

I second the hop oil comment. I just did a new method where all my hops were kept in a grain bag (instead of half of them getting poured in the fermentor), so we'll see if this wit I just brewed has it.

I've gotten it with Belgian yeast and longer secondary aging. I wouldn't worry about it.