[Wort-H.O.G.]

WL vials being a month old were already at 75% viability

That is for slurry stored after a fermentation, though. Stored properly, a lab propagation won't degrade that quickly.

ok understood, thanks for that.  its just all the yeast calcs Ive used seem to account for yeast in vial or pouch that way when determining viability...using the manufacture date and 4-month scale.

EDIT: doesnt quite equate to 25% viability reduction for 30 day old yeast in the calc.....its 21%

[S. cerevisiae]

But to play devil's advocate here, I've read on this forum that the Macro brewers ferment at 1-2 atmospheres.  Wouldn't that introduce a CO2 toxicity problem?  Or is that just a yeast storage thing?  Confused 

Fermenting under pressure also takes its toll on yeast cells. 

http://download.springer.com/static/pdf/215/art%253A10.1007%252Fs00253-004-1648-9.pdf?originUrl=http%3A%2F%2Flink.springer.com%2Farticle%2F10.1007%2Fs00253-004-1648-9&token2=exp=1438290464~acl=%2Fstatic%2Fpdf%2F215%2Fart%25253A10.1007%25252Fs00253-004-1648-9.pdf%3ForiginUrl%3Dhttp%253A%252F%252Flink.springer.com%252Farticle%252F10.1007%252Fs00253-004-1648-9*~hmac=9befdb57201b17ed0d720c6cbed0cad9dd70f0309adbb2335d19bb13a190c369

[S. cerevisiae]

That is for slurry stored after a fermentation, though. Stored properly, a lab propagation won't degrade that quickly.

+1

Lab grown yeast contains mostly young cells whereas the average age of a cell in a cropped culture is highly dependent upon cropping/repitching technique.  I have heard Garrett Oliver state on more than one occasion that the Brooklyn Brewery underpitches periodically in order to reduce the average age of the cells in the culture.

[Wort-H.O.G.]

That is for slurry stored after a fermentation, though. Stored properly, a lab propagation won't degrade that quickly.

+1

Lab grown yeast contains mostly young cells whereas the average age of a cell in a cropped culture is highly dependent upon cropping/repitching technique.  I have heard Garrett Oliver state on more than one occasion that the Brooklyn Brewery underpitches periodically in order to reduce the average age of the cells in the culture.

And so would a lab culture in a vessel that  allows co2 to escape encourage slower degradation? Curious because of the stated longer viability of 6 months stated on pure pitch.


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[brewday]

I just picked up the 001 & 002 pure pitches dated July 13th for $5 each - couldn't pass that up.  I think I'll take a leap of faith and give the 002 a go for my BrewUnited Brown Porter.

[Wort-H.O.G.]

I just picked up the 001 & 002 pure pitches dated July 13th for $5 each - couldn't pass that up.  I think I'll take a leap of faith and give the 002 a go for my BrewUnited Brown Porter.

Cant speak to 002 but 001 you should have no issues based upon my experience.


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[S. cerevisiae]

And so would a lab culture in a vessel that  allows co2 to escape encourage slower degradation? Curious because of the stated longer viability of 6 months stated on pure pitch.

Theoretically, yes; however, there are other factors such strain robustness and storage temperature.

[Wort-H.O.G.]

So Irish ale and English ale yeast in pure pitch are out in my lhbs now. Want to plan brews with these soon pitching one pouch. Just picked up Jul 21 production of wlp001 to run an IPA with it next week. Likely push a little higher OG with this one.


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[ynotbrusum]

I've got two five gallon batches of WLP 004 going in an Ordinary Bitter (1.040 O.G.).  I figured the lower the better for OG.  Then try repitching into a larger beer.  The yeast certainly looked very healthy and were one month old.  Let us know how it goes and I will do the same.

[Wort-H.O.G.]

Brewing an all challenger 1.051OG, 50ibu English pale ale this weekend or next with one pouch wlp002 pure pitch.


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[Wort-H.O.G.]

Update- The WLP001 beers have come out great. No flaws and all as expected.

The WLP002 was 1.051 OG and finished 1.010. It was UK Challenger PA. The pure pitch was 4 weeks old when pitched directly into wort. Absolutely a fantastic representation of English Pale Ale- 8C.

Looking forward to additional strains and brews with pure pitch.

[dkfick]

I think increased purity and better packaging are both pluses.  Seriously I was surprised to hear people say they prefered the preforms... I always hated shaking the crap out of them... Then dealing with the potential volcano when you try and remove the lid.  If I can just rip the top off this new packaging and just pour and push the yeast out like toothpaste into my starter I'll be a happy camper.

[Wort-H.O.G.]

I think increased purity and better packaging are both pluses.  Seriously I was surprised to hear people say they prefered the preforms... I always hated shaking the crap out of them... Then dealing with the potential volcano when you try and remove the lid.  If I can just rip the top off this new packaging and just pour and push the yeast out like toothpaste into my starter I'll be a happy camper.

agreed. shaking the crap out of a vial, especially the chunky strains was annoying. its more like wyeast now and pours out nicely.

[Wort-H.O.G.]

the one pure pitch wlp002 made one fantastic UK Challenger PA. 1.052 OG and finished at 1.008.  cant wait to get it carbonated, as sample is really nice already.

EDIT: recipe was 95% maris, 3% 80L crystal, 2% 165L extra dark crystal. 40IBU all challenger.  mashed 149F 5.4PH

[ynotbrusum]

For the record - I had great success with the 004 Pure Pitch in 5 gallons of ordinary bitter at 1.041.  Finished quickly (as expected) and I have repitched it into an Irish Red 10 gallon batch at 1.055.  Also , I have a side by side 5 gallon Ordinary Bitter with one using 002 Pure Pitch and one using S-33 as a taste comparison.  The 002  took off slightly faster than the rehydrated S-33, but only by a few hours.  So far, Pure Pitch seems to be a  highly viable product (pun intended) at least to this brewer.