80 hours and no fermentation; infection risk?

[slsBrewing]

Brewed a 5 gallon batch of OG 1.054 pale ale on 6/20/15 and split into two 3-gallon better bottles. Pitched a vial of wlp007 Dry English into one and a vial of wlp051 California V into the other; appropriate amount of yeast pitched. Ferment controlled temp of 66F. The best used by date on the 051 is July 2, 2015. Slow start as I probably under oxygenated. 007 fermentation started around 56hrs and is going strong. It has been over 80 hours and no fermentation in the 051!

I swirled both better bottles at 32 hours, and swirled the 051 again at 68 hours. I know that I need to repitch. I will probably pitch another vial of 051 or make a starter with 051 or another yeast and repitch. My concern is infection. I practice very good sanitation; but nothing is perfect. Should I be worried about infection? How can I tell if there is or is not infection?

 

[PoppinCaps]

Besides pulling a sample and looking under a scope, only time will tell if it's too late. If it were me, I would reoxygenate and get a proper amount of fresh yeast in there quick. It will be said, so I may as well be the first, with any liquid yeast, only a starter will confirm it is a proper pitch, too many hands in the supply chain to go only on manufacture date. I would dump 2 fresher vials in the 3 gal since a starter would take too long. Or forego the 051 and put a packet of dry yeast in, that would probably be the best option.

 

[peterj]

appropriate amount of yeast pitched. Ferment controlled temp of 66F. The best used by date on the 051 is July 2, 2015.

This was not even close to an appropriate amount of yeast. Since it was so close to the best by date, you really needed to make a starter. According to the Mr. Malty calculator it was probably only at about 20% viability when you pitched it. So you needed ~94 billion cells but you only pitched ~20 billion. That's a big underpitch. And as PoppinCaps said, depending on the quality of the supply chain, who knows what the actual viability was.

After 80 hours of zero activity, I would be starting to get worried about infection. The above advice was good about pitching more yeast as soon as possible. I wouldn't wait to make a starter, either a couple vials of 051 (or whatever you have quick access to) or some dry yeast.

Just to be sure, are you positive there hasn't been any activity? No krausen ring on the sides or gravity change that you might have missed? It would probably be pretty obvious in a better bottle though.

 

[slsBrewing]

According to the Mr. Malty calculator it was probably only at about 20% viability when you pitched it.

Thank you for pointing this out! I had not noticed the "production date is 4 months prior to the best by date" language on mrmalty before. I knew viability dropped with age but did not know how to account for it in wlp vials.

I always make starters with my 5 gallon batches in a single carboy. Being the second time using the 3-gal bottles, I was afraid I would be over pitching. But now I know otherwise.

 

[slsBrewing]

Better late than never... The 007 batch finished up and cleared nicely so I bottled it. It produced a decent beer that looked beautiful but had some weird flavors probably from the stressed yeast (due to underpitching). The 051 batch received a pitch of 007 I had in the fridge. It took off but never cleared; dumped that one down the sink. 007 on the left, 051 on the right: