Portion of my wort acting like a starter

[Ravenshead]

Here's the story:

I brewed a porter with an OG in the mid to high 60s. I wound up up with just under 7 gallons instead of the expected 5.5. There's a long story about how that happened but it doesn't really matter, suffice to say I have more wort than one carboy can hold. I put about 6 gallons in my 6.5 gallon carboy with a blow-off tube and pitched a pack of SA-04. The remaining gallon or so went into an apple juice jug along with some washed SA-05 I had in the fridge. Both yeasts were pitched around 3:00 yesterday afternoon.

The main carboy is still at high kraisen and blowing out the tube as we speak. The gallon jug however looks like a starter does the day after you start it-a small kraisen residue ring on the side of the container and a nice layer of yeast on the bottom. All other signs of fermentation were absent and the SG was still around 60. It's a great looking stater but I wanted it to be beer.

Does anyone know why the small portion is acting so differently?

Also, I was too lazy to go get more yeast so I re-routed my blow-off tube to the small carboy to try to get the fermentation going again. We'll see how well that works.

 

[banik]

If the small one is fermented out, then it's almost definitely the differing pitch rates vs available sugars.

 

[BBL_Brewer]

How old was your washed yeast? Might take a minute to perk back up. Tossing in some yeast from the blow off shouldn't hurt as long as sanitation doesn't fall to the wayside. I'm sure it will ferment eventually.

 

[Ravenshead]

The yeast was around 4 months old. I don't think it fermented out so much as it just replicated itself and them went to sleep. I started with about a 1/2 in. layer in a pint mason jar and had a full inch layer in the bottom of a gallon jug this morning. I wish my starters would do that when I'm trying.

I'm just curious if there is some difference other than batch size that causes a wort to behave like a starter rather than a full fermentation.