Infection? Maybe Not

Hey Folks,
Below is a picture of the top of our fermenting stout.
We fermented this at 18c (64f) for 1 week (ambient room temp) and then I let the temp rise to 20c and then 21c over the course of 3 days. There was a thin layer of krausen on top when I started the temp rise. I give it a taste prior to the temp rise, and it was delicious. Yesterday I saw "this" and it gave me a bit of worry. I will taste it again tonight, but figured I would throw the pic out to see what your thoughts are on it.
Thanks in advance for your insight.

Yup that's a good looking infection. What's with all the headspace?

that's f^&%ing gross LoL

daksin said:

Yup that's a good looking infection. What's with all the headspace?

Click to expand...

I'm in China, fermenters are what they are. That would hold 15g, but we brew in 10g batches.

Have you tasted it or taken a gravity reading? Give it a taste before you do anything else. Might be wild yeast that's reacting with the o2 in that big head space.