I need some help and/or opinions for kicking a Cal V yeast back into action. I brewed an APA...actually...IAPA
since my efficiency ended up around 85% rather than my planned 72%
Batch size ~10.5 gal
OG - 1.064
60 minute sac rest at 151F
Mash Ph 5.4
Wort Ph 5.2
Aerated wort with fish tank pump and filter thru .5 micron stone ~20 minutes.
Pitched (2) 0.5L starters of WLP051 @ 63F and allowed to free rise to 68F over 2 days
Fermenter: Blichmann 14gal TC conical
Since I'm fermenting in the conical I rely on the air lock for signs of activity. Saw activity within 12 hours and went "vigorous" within 24 hours. After 5 days activity slowed down, so I took a sample at 1.028. At day 7 (today) took another sample at the same 1.028.
I'm worried that while still active, it is slowing significantly and possibly stalling out. So, I'm looking for opinions to get this thing going again. Should I:
1) Rouse the yeast by blowing CO2 through the racking arm (waiting on replacement of lost gasket due to arrive tomorrow)
2) Add yeast hulls (on hand)
3) Add yeast hulls and rouse the yeast
4) Add a WLP001 starter at peak to clean up after the WLP051
I've heard this yeast is somewhat temperamental. I've never used yeast hulls. Do they require hydration? I can't imagine they do since they are not alive. Thanks for any suggestions.