Low attenuation after reharvesting yeast.

[beerkench]

I don't often repitch yeast but decided to repitch the Nottingham I'd used in my previous batch as it wasn't tainted with dry hops.
The original batch was a 1.059 beer pitched with 2 packets of dry Nottingham, mashed at 151, aerated by shaking and fermented at 63, finishing at 66. It finished out at 1.012 within 5 days and I considered it to be a healthy fermentation.

I didn't rinse the yeast but simply filled 3 sanitized jars equally (often recommended way to do it on here) with the slurry and put them in to the fridge.
So for my next batch, a 1.060 beer, brewed only 7 days after collecting the slurry, I pitched one of the jars of slurry directly into the 151 mashed wort, aerated by shaking and fermented at similar temps to the original batch.
It didn't take long to start up but was more sluggish than the original pitch and took 7 days to reach 1.018 which now appears to be the Fg as it has stood at that for 4 days.
Any ideas why it has stopped there? I know it's not too high but it should go lower with it being Nottingham.
I wonder which part of my practice is bad? My main guess is that the repitched yeast needs more oxygen than 2 packets of dry yeast or that I should have rinsed it to get the best of it.

 

[jimbobbillyray]

How long after you took the slurry from the fridge until you pitched it ?

 

[beerkench]

I pitched it direct from the fridge as I heard that's what Jamil Z does.


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[jimbobbillyray]

Update??

You may also want to post this in the "yeast and fermentation" forum- I'd guess some folks there would have some ideas?

 

[beerkench]

Ok thanks, I will try.

 

[pablosbrewing]

I pitched it direct from the fridge as I heard that's what Jamil Z does.


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Slowly warm it to ferment temp first.

In the book Yeast, Chris and Jamil advocate making a small starter from harvested yeast.

 

[mkeomotupp]

I'd guess some folks there would have some ideas?

 

[jwalker1140]

I struggled with this exact issue for nearly a year. The solution for me was to add Wyeast yeast nutrient to the batches that I'm repitching slurry into. Now, my fifth generation ferment is as good or better than my first. YMMV. Good luck getting it sorted out.

 

[TheHappyHopper]

I pitched one of the jars of slurry directly into the 151 mashed wort...

I hope I'm reading that wrong (or it was a typo) - you didn't pitch your yeast into 151 degree wort, did you? If so, I'm surprised ANY of your yeast survived.

 

[ScrewyBrewer]

I pitched it direct from the fridge as I heard that's what Jamil Z does.


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I always take my yeast out of the refrigerator on brewday morning and let it slowly rise to room temperature as the brewday progresses. From what I've learned the yeast cells do not like rapid changes in temperature, so going from 34F to 65F so quickly might be enough to set them back. If you're not sure if that's the cause try making a starter a few days before pitching the yeast directly into your wort.

 

[beerkench]

I struggled with this exact issue for nearly a year. The solution for me was to add Wyeast yeast nutrient to the batches that I'm repitching slurry into. Now, my fifth generation ferment is as good or better than my first. YMMV. Good luck getting it sorted out.

Good tip thanks.


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[beerkench]

I hope I'm reading that wrong (or it was a typo) - you didn't pitch your yeast into 151 degree wort, did you? If so, I'm surprised ANY of your yeast survived.

It was a short way of saying 'Wort that was mashed at 151'


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