Bacteria gunk? Or just yeast waking up?

[Cap'n Jewbeard]

Sorry, sorry, I promised I'd never post an "Is this infected," but... is it?

I'm about to bottle this (or throw it away if it tastes terrible), and here's the deal:
It's a lager that's been in the fridge for about 3 months. (This is the same April-zen Oktoberfest that had all kinds of issues on brew day, stemming from the bazooka tube falling off). I took it out of the fridge 2 days ago, and it's possible the yeast are just reviving and making this happen. What do you think?

Some of the clumps of bubbles have a brownish/yellowish tinge to them, which is what concerns me.

 

[BigFloyd]

What temp has it been at since you removed it from the fridge? Using lager yeast?

Did it look like that when you took it out or has it developed over the last 2 days?

 

[unionrdr]

I was wondering myself,since all that fridge time may've forced a lot of the co2 blanketing it back into solution. It's def some krausen...but the look of it also makes me wonder if something else is developing?

 

[Cap'n Jewbeard]

Yes, it's the southern german lager yeast. It's been at about mid-70s the last 2 days (just room temp).

When I took it out of the fridge there was nothing at all on the surface except maybe a tiny bit of film, so all of that is new.

 

[pfgonzo]

That's probably off gassing then. Cold liquid (from the lower fermentation temp) holds more C02 than warm, and when you warmed it for the diacetyl rest, some bubbled out. What you have there is proto-head!

[edit] This isn't a 100% bright-line rule of thumb, but after looking through every page of the "Post Your Infection" thread, I find the following generally applicable: "Brown and Green is simply clean, but White is never right."

Like I said, not always 100% true, especially if the brown is fuzzy, but your bubbles look a-ok to me. If you start seeing anything that's pure/bright white, then you have a problem.