Infection Identification

[jm]

I brewed this stout about 5 months ago and it's been sitting in the carboy in the cellar since then. About a month ago I noticed white round dots floating on the surface and a milky residue around the edges of the glass. It tasted fine so I racked it into a new carboy to see if this gunk would return. Attached are pics from the last few days, first large milky looking bubbles formed but today it's lots of little bubbles.

Some research suggests it looks like brett, lacto etc...

Anyone had similar growth?

[MrC]

I've never had anything that looked like that but from what I've seen online it certainly looks like an infection, especially scum1.jpg.

How does it smell? Vinegar?
How does it taste? Sour? Acidic? Astringent?
Is it pleasant or offensive?

Check this out and see if you can narrow it down based on flavour & aroma:
http://www.kroc.org/Links/TroubleshootingGuide.htm

[Michael]

I have had a beer look like this that tasted just fine.

[jm]

Just took a sample and I can't taste any off flavours. I guess I'll give it a couple more weeks and bottle if nothing changes.

Thanks guys.

[Grant R Baker]

It'looks' like a yeast reaction... which can happen.

.

During normal fermatation the yeast easts most of the sugar but when transferring it to a carboy the yeast often comes back to life and ferments some more.

.

Best said "It doesnt' look furry" .. so bottle it, try it.. and if you don't go blind or have to pray to the porcelin then yer good.

[Mark Jackman]

Its a bit hard to tell from the photos but it doesnt look like anything too scary.  If it smells and tastes fine, its fine. 

[MrC]

I agree that if it smells fine, tastes fine, doesn't make you feel ill and doesn't leave you with a nasty hangover then it's fine. I'd still keep an eye on it though just in case it is infected but you can't tell and you end up with bottle bombs.