Wheat beer fermenting. I haven't added yeast yet!

[Dukester]

Okay, so I brewed up a batch of wheat beer and put it in the fermenter. The plan was to let it get down to pitching temp overnight while my starter finished getting ready. This morning I wake up and see the brew has already started a small ferment? Do I pitch the yeast anyway and hope it will take over from whatever wild yeast may have found it's way in there?

Cheers,

Dukester

 

[FatsMcBrew]

How do you know it has started to ferment?

 

[R2-D2]

The bubbles you are seeing are more than likely being caused by the air being forced out of the fermenter as the liquid volume expands. Hot-to-warm wort is .95 the volume of cool-to-room temperature wort. So, that 5.5 gallons of hot wort is going to expand to 5.8 gallons of cool wort. In my bucket that volume is equivalent to an inch. The cooling effect is slow and thus the air being pushed out is going to be slow. But, it's going to stop soon.

Pitch the yeast.

 

[Runyanka]

wild yeat will not take hold that fast even if you tried. Pitch the yeast and RDWHAHB!

 

[Dukester]

I can't say for sure that it was fermenting. There was definitely some noticeable bubbles working their way up from the bottom. I don't think (but then I don't know) that it was from the expansion of the wort. It was down to 80F when I put it in my brew room and went to bed and 68F when I got up for work in the morning (that room stays pretty chilly).

If the wild yeast won't get started that fast, what was bubbling away in my fermenter? I haven't had that happen in any of my previous batches so I'd be curious to know what caused it? It was only a very slight, but noticeable activity in the airlock. I don't know what caused it, but it looked like fermentation activity to me. I'm looking to learn here so if anyone can help me pin it down, I'd appreciate the knowledge.

Either way my 1L WLP320 starter is now very hard at work so I think whatever it was got creamed by the starter.

Cheers,

Dukester