Infection

[mrbean]

What kind of infection do I have here? Should I cold crash to stop it right now or let it fully ferment out? Last time I checked it was at 1.020 and was completely dead, I took off the top and gave it a gentle stir with a sanitized instrument, and now I have this white gunk on the surface. The airlock is bubbling again but I don't know if that's from the yeast or from the source of infection. Thankyou.

 

[mrbean]

The airlock fluid is now moving back downwards rather than up and out.

 

[flars]

Stirring the beer probably caused some off gassing of CO2 to start the bubbling through the airlock.
If the material on the surface doesn't turn fuzzy it is most likely yeast that was stirred up. Difficult to tell in the picture.
The downward movement of the liquid in the airlock is due to pressure change from the CO2 release diminishing.

 

[mrbean]

I found a similar picture to mine on here, his is much mare advanced than mine, but I guess I should so this now:

I would rack under the pellicle and get it kegged and chilled...guessing the cold temps and lack of o2 will either slow or stop the infection. I had one batch that was exposed w/ too much headspace and started to skin over, and simply kegged it w/ no real adverse taste...of course YMMV.

 

[Denny's Evil Concoctions]

Looks like a Pedio or Lacto infection. How sour is it? Lacto sours a lot quicker.

And yes, racking and kegging very cold will slow any further growth considerably.

 

[mrbean]

Looks like a Pedio or Lacto infection. How sour is it? Lacto sours a lot quicker.

And yes, racking and kegging very cold will slow any further growth considerably.

I didn't taste it but it smelled slightly sourish. I have kegged and now cold-crashing, but I noticed something floating on the surface at the top of the keg. I hope the cold crashing will get rid of it somehow.

At least I learned something from this experience; I had a homebrew meet up and for that I bottled from the fermenter, in doing so I removed the airlock so as not to get the airlock liquid into the wort. I guess this is what caused the infection - allowing oxygen and wild yeast or bacteria in when adding wort to a bottle. Will not do that again.

 

[mrbean]

It's now kegged and carbed , the taste is good, very slightly sour, but the smell is not nice, it's off-putting even though it tastes OK.

I'm thinking to get some fresh aromatic hops to dry hop in the keg in order to mask that sour bacterial smell. Would that do the trick?

I will use clothes pegs on the nose but other than that do you have any good ideas for eliminating the sour smell? Cheers.