Oil Slick in beer

So i'm curious about this oil slick thing in my beer. Everything went fine throughout the whole process. This was my first attempt at a partial mash and I did deathbrewers Franziskaner Dunkel clone. The mash went good except for some minor temp changes, give or take 3 degrees ( I also used his apartment partial mash method, mashing in a kettle on the stove). Fermentation was normal as well. Nothing out of the ordinary. So I bottled and it's ready to drink now. Taste is great! But every one i've poured so far has had this small oil slick on the top of the beer after the head goes away. It's bugging me. Any ideas?

Did you clean all your equip with hot water and soap before sterilization, sometimes I get stuck with the same problem, maybe also your glassware?

The glassware was pulled directly from the cabinet with nothing done to it before pouring the beer. Our glasses are washed in the dishwasher, then thrown in the cabinet. Maybe thats it. I usually don't use soap when i'm cleaning my brewing equipment before brewing. Just hot water and sanitizer. The bottles were washed in the dishwasher w/ detergent (wasn't thinking) on sanitize mode. Now that I think about it, that could be problem right there, the detergent in the dishwasher.

Mantis said:

Now that I think about it, that could be problem right there, the detergent in the dishwasher.

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That would be my guess. Sounds like you have soap on something, either the glass or the bottles.

that is probably exactly your problem. A lot of dishwashers tend to leave a small amount of residue, and while it generally goes unnoticed, it can really screw with your (beer's) head.

detergent would affect head retention. at least if you clean the bottles with it, not sure about the glasses. how did you aerate your wart?

TipsyDragon said:

how did you aerate your wart?

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Put a stopper on the carboy and shook it up to the best of my abillity. More like a vigorous jostling actually.

ok thats good. i've heard of people using vegetable oil to aerate their wart. this would be a rather obvious source of an oil slick on your beer.

you could use a fish take aerator and air-stone with an inline air filter to aerate your wart. makes the job much easier.

aeration supplies

What did you use to sanitze your equipment? I hear that some commercial sanitizers (like Starsan) can leave an oil slick on the top of your beer.

I use one step to sanitize. I know it gets mixed reviews, but it's cheap and I've never had any infection issues.

Marshach said:

What did you use to sanitze your equipment? I hear that some commercial sanitizers (like Starsan) can leave an oil slick on the top of your beer.

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I experienced this last night in my Imperial Stout after I sanatized with Star San. It's probably nothing to worry about, probably just from your one step.

What about the oils from the hops? Could they cause an oil slick-type appearance?

i notice this on the top of my primary fermentations when i don't empty out all the starsan, it hasn't caused any into glass problems though... i'd put my money on the dishwasher residue.

next time i'm going to skip the dishwasher detergent for sure next time i sanitize my bottles.

I just read a thread on how to prepare your glasses for homebrew, even if you washed them with soap, so I'm also going to give that a try.

Here's the link if you're interested.