Infection?

[deadlydes]

I am posting this on behalf of a mate who doesnt post on here.

he went to check the SG on his current fermenting beer (5 days since pitching) last night. took the lid off and the liquid surface was covered in a white film. it looked fairly disgusting.

any idea what it is? i havent seen anything like it before.
i am guessing it was an infection. its looks pretty much the same as my vinegar culture!

it smelt slightly vinegary (not overly though) and tastewise it was ok, slightly sharp maybe.

we decided to chuck it but just want to find out for curiosity sake.

[PieOPah]

Some people have in the past mistaken normal clusters of C02 bubbles for mould.

Personally I would have let the beer mature to see if it was okay especially if it tasted okay.

[Orfy]

Yeast can clump around co2 bubbles and give the appearance of white floating mould. As long as it's not stringy or real hairy you should be okay. CO2' yeast and alcohol smell quite sharp

[mysterio]

I agree, beer while in the fermenter smells quite bad. Give it time.

[steve_flack]

Is it a pellicle like you get in Lambic brewing? It's formed of all sorts of beasties such as Brettanomyces etc

There's a picture here http://www.liddil.com/beer/photo/photo6.html

This is not a good thing to see in a normal beer.

[PieOPah]

I had a beer in the fermenter which had lots of white spots floating on the surface. Looked a lot like mould but was difficult to tell through the murky sides of my Better-Bottle.

After about 10 minutes of intense staring, I finally saw a little gap appear in one of the specks - just like a bubble bursting.

Next day the number of spots had drastically reduced. Beer is now kegged and samples tasting great.

[monk]

I had a beer in the fermenter which had lots of white spots floating on the surface. Looked a lot like mould but was difficult to tell through the murky sides of my Better-Bottle.

After about 10 minutes of intense staring, I finally saw a little gap appear in one of the specks - just like a bubble bursting.

Next day the number of spots had drastically reduced. Beer is now kegged and samples tasting great.

I often have these kind of spots on the surface, too. Like yours, they tend to disappear, mostly, and the beer tastes good. I wonder if it isn't just a combo of krausen residue and some hop oils or something.

Monk

[ray.norfolk]

From what you discribe, the infection is almost certainly a wild yeast named mycoderma. It is airborn and is often seen in pub cellars on spilled beer. It contaminates the beer from the surface so your friend will have to be almighty careful not disturb the skin of infection when he racks the beer. He would be wise to discard the last 2 -3 inches as, if it gets mixed into the beer, it will sour it quite quickly.

In what room does your friend ferment his beer - is there an air flow which could carry the infection? And does he cover his fermenter which in normal circumstances should be adequate.

Ray

[NzDan1]

I had my first infection a few weeks ago, a thin bubbly white film over the top, looks kinda dry and powdery, I left a few inches behind on racking and haven't had a problem with it (yet)!