Bizarre Non Fermentation of S05 Repitch

[smata67]

Days ago I was bragging about how I had never had a problem re-pitching yeast in 50 batches. Should have kept my mouth shut. Brewed a 10 gallon batch, split and pitched in some Hansen and S05, both from recent batches. I started them both yesterday, side by side, in 2L mason jars, about 100ml slurry into 1L at 1.040. By evening, both had activity and krausen, smelled fine, no problem. Chilled both 5 gallon batches split from the same boil to 80F and pitched the yeast which has been sitting side by side on the counter at 75F. 24 hours and Hansen is chugging along, nothing at all with the other batch, zero lock activity, no movement at all. I'm completely dumbfounded. The only difference would be the steeping grains and the hops used. Can't really suspect either, everything looked on the up and up. Cannot figure this one out. I do have fresh Kveik to pitch and have that coming to room temperature, we'll see if that fares any better.

 

[RPh_Guy]

That is weird.

Do you use to water and/or add zinc?

Some bacterial contaminations can cause a sluggish fermentation.

 

[eric19312]

I usually pitch about a pint of slurry into a 15 gallon batch with US-05 and its not unusual in my experience to have to wait 20-36 hours for airlock activity. I don't bother with a starter unless the yeast is old. Usually my yeast is very fresh...either harvested that day or is about a week old. You mentioned your yeast was from recent batches...how recent?

 

[smata67]

The S05 slurry was harvested on 8/5/19. Like I said, the starter behaved hand in hand with the Hansen, krausen after 6 hour or so, and done overnight. It was only 1L at 1.040 with an estimated 200B initial cell count, it made hash of that. Heavily aerated and yeast nutrient added to both batches. I just popped the lock at 24 hours to drop in 5 teaspoons of Opshaug slurry (for reference, I have pitched 1-1/2 teaspoon in the past of this yeast into 5 gallons and got activity overnight and fermented out to 1.013, so this is a heavy overpitch, essentially 2 WL vials, but my OG is 1.080). The batch smelled of fresh wort, no fermentation products detectable by nose. Hopefully, will see some activity in the morning. I just can't imagine why there would be nothing at 24 hours given these circumstances. I should have seen activity this morning like with the starter and other batch.

 

[kh54s10]

It is puzzling.. I have never re-pitched US-05 but my starters (never with US-05 either) have always started by morning. US-05 rehydrated or sprinkled has always started before 24 hours. In my 109 batches only one or two have not started in 24 hours, no matter the yeast.

Hope you see activity in the next 12 hours. I would wait as long as 72 hours before a re-pitch (probably).

 

[smata67]

Six hours later and a very vigorous fermentation in progress. I have to believe it's the Opshaug doing its thing. Will keep at 70 and hopefully avoid any off S05 flavors. Don't know what to make of the lack of S05 peformance, maybe I'll make another starter with a remaining sample.