Pitching Slurry

[Nubiwan]

Old yeast is pretty much dead yeast. So in reality, you are under pitching the batch with tired cells. Not a great head start! Not only is there a risk of off flavors but the batch more than likely will end up under attenuated. Basically the yeast might poop out before the job is done. Did you make beer? - yes. Could you have made better beer with improved yeast handling? - probably

I have gone to yeast freezing as opposed to yeast harvesting. Yeast harvesting favors pro breweries that brew with the yeast over and over, back to back. Yeast freezing allows one to pick a vial, grow it up on your schedule and pitch lots of healthy yeast. It might be a good alternative if your schedule is varied.

Yeah, could be. We shall see. If I do hit 1.010 or a.012 FG, does that mean I am in the "attenuation" clear?

as for taste, I can really only judge against any beer I make myself, and stuff in the store, and since my grain bill changes once in a while, its difficult to know what the cause might be, if taste is altered, or funny.

Off flavours? What does that taste like in beer? Sourness? Tartness? Vinegar? Alcohol? Nutty? Cardboard? Skunky? Some people actually aim for these characteristics. Can honestly say I have yet to make a beer that I could not drink, except for one wheat beer I made about 6 years ago, and is still probably in bottles under my empties.

So, will wait with eager anticipation the results of my old slurry test.

 

[Nubiwan]

Old yeast is pretty much dead yeast. So in reality, you are under pitching the batch with tired cells. Not a great head start! Not only is there a risk of off flavors but the batch more than likely will end up under attenuated. Basically the yeast might poop out before the job is done. Did you make beer? - yes. Could you have made better beer with improved yeast handling? - probably

I have gone to yeast freezing as opposed to yeast harvesting. Yeast harvesting favors pro breweries that brew with the yeast over and over, back to back. Yeast freezing allows one to pick a vial, grow it up on your schedule and pitch lots of healthy yeast. It might be a good alternative if your schedule is varied.

Thanks Bassman.

Sincere questions here: Not my intent to be confrontational, but I always strive to make my process as simple as possible. Out of either cost and/or time constraint.

Is what I bolded a factual or anecdotal comment, or even from personal experience? Have you ever pitched really old slurry and tasted the result? Underpitched?

Will it make a difference there is some dead yeast (perhaps 15 oz) going into my 7 gallons of beer?

Will under pitching make bad beer, or simply just means it takes longer to kick/finish?

Much of my process does not conform to accepted brewing norms. Pretty sure if people saw they way I conduct my mash, they'd start having babies. But I still make a decent beer. Anecdotal right there

 

[Bassman2003]

Well, these things are always in proportion. In theory, underpitching tired cells will force the few remaining cells to be overworked in making enough cells to complete the fermentation properly. Stress on yeast cells results in different behavior than when not stressed. Which means the yeast create more by-products and are too tired at the end to go back and clean them up. So two strikes against having a good to great fermentation. BTW, I am often looking for 1.008 for a "good" fermentation. 1.012 would be considered a miss for a 12-13 plato beer.

Will this always result in a spit-take when you drink the first sip? Probably not to varying degrees. I recently tried to pitch a 3 month old slurry of lager yeast. It did not go well as I had to grow up a 2nd starter as well as add some carbonation yeast (CBC) because I could not get enough yeast activity to naturally carbonate the beer alone. The beer tastes good. So in this example, if I had left the yeast alone without adding any other cells, it would have finished in the high teens, (almost 1.020) and who knows how much would have been cleaned up without the new round of yeast thrown in to finish the job. Maybe it would have tasted fine but been under attenuated.

I have brewed for 20 years and the one area to focus on to improve and make sure your beer is good to great is yeast handing. Hands down. You can mash in whatever fashion etc... The end result will be most determined by the yeast handling/temps etc... I will be finishing up my yeast freezing video soon. Hopefully that can be helpful to those who want a better way to use and store yeast. Check my channel in the sig. in a week or two.

 

[Nubiwan]

As an update, both beer sitting at 68 degrees in my ambient-ish basement. Temps returned to normal summer standard down there. The slurry I assumed to be more recent hasn’t quite got going yet. Still building a head of steam in fermentor, and air lock pressure visible. That’ll be 48 hours lag from pitch, even though it’s arguably building up.

So it’s been slower than my other slurry, which I had no real record on, but I assumed even beyond 6 month old. That first batch now sitting at 1.014 this AM, and still going. So nearly done in 4-5 days seems pretty average.

 

[McMullan]

As an update, both beer sitting at 68 degrees in my ambient-ish basement. Temps returned to normal summer standard down there. The slurry I assumed to be more recent hasn’t quite got going yet. Still building a head of steam in fermentor, and air lock pressure visible. That’ll be 48 hours lag from pitch, even though it’s arguably building up.

So it’s been slower than my other slurry, which I had no real record on, but I assumed even beyond 6 month old. That first batch now sitting at 1.014 this AM, and still going. So nearly done in 4-5 days seems pretty average.

In healthy yeast, a lag phase - the time taken for yeast cells to remodel their metabolism, to adapt to the new conditions - takes several hours, not 2 days. Such extended, suboptimal delays to fermentation starting provide time - a window of opportunity - for grist and hop derived reactive oxygen species to initiate stalling reactions promoting product instability and development of off flavours downstream. Not helped by the risk of contaminating bugs establishing in the wort just waiting there at a cosy (bug-friendly) temperature. Nor by pitching poor quality yeast cells, including a high proportion of dead ones. The chances of producing a stable nicely-balanced quality beer are relatively low. When, if, it reaches its peak, in terms of drinkability, I'd recommend consuming it very quickly. I doubt it's going to remain in 'peak' condition for very long. A week or two at the most, potentially.

 

[Nubiwan]

In healthy yeast, a lag phase - the time taken for yeast cells to remodel their metabolism, to adapt to the new conditions - takes several hours, not 2 days. Such extended, suboptimal delays to fermentation starting provide time - a window of opportunity - for grist and hop derived reactive oxygen species to initiate stalling reactions promoting product instability and development of off flavours downstream. Not helped by the risk of contaminating bugs establishing in the wort just waiting there at a cosy (bug-friendly) temperature. Nor by pitching poor quality yeast cells, including a high proportion of dead ones. The chances of producing a stable nicely-balanced quality beer are relatively low. When, if, it reaches its peak, in terms of drinkability, I'd recommend consuming it very quickly. I doubt it's going to remain in 'peak' condition for very long. A week or two at the most, potentially.

While not encouraging, thanks for this.

Guess I’ll wait and see what my “finished” product ends up like, and how it holds up. I wonder the beer style impacts the amount of degradation experienced. That is, a lager versus darker ales. The former rather pronouncing process issues more than the latter.

Have used ascorbic acid with a degree of success in IPAs to reduce oxidation and loss of hop flavour. Something I could try here.

All the same, never had a beer go bad, as it got older. Certainly not within weeks. Can I ask your source for the claim. Evidence?

 

[Bassman2003]

I don't think the term "go bad" as in rotten is what is meant. More like descend into off flavor dumper territory. Life is too short to force your way through a marginal keg of beer. Dump it, get some fresh yeast and make some good stuff!

 

[Broken Crow]

Is this a good point in this thread to just mention that "Pitching Slurry" would make a great name for a band?

 

[McMullan]

Is this a good point in this thread to just mention that "Pitching Slurry" would make a great name for a band?

Slurry and the Pitchers first track 'Ferment This'. I like it

 

[Broken Crow]

Slurry and the Pitchers first track 'Ferment This'

Second track: 'Wort the F**k"

 

[McMullan]

Followed by 'It Better Wort This Time'.

 

[Broken Crow]

Fourth track: 'Yeast Infection (An Ode to my Ex)'

 

[McMullan]

'The Number Of The Yeast', a collaboration between Slurry and The Hemocytometers.

 

[McMullan]

'Oxygenated Wort' with a  drunk drum solo. 'High Krausen' with a guitar solo. "Dry Yeast Starter', a moving ballad of acceptance over denial. That's almost an album so far

 

[Dland]

"You never have to slurry when yer pitchin cone to cone"

Perhaps a country tune.

 

[McMullan]

"You never have to slurry when yer pitchin cone to cone"

Perhaps a country tune.

How about 'The Dry Yeast Went Down To Georgia'?

I like it


Obviously, that young man, Johnny, made a starter and the devil didn't

 

[Dland]

I think we might be getting off topic..{;

 

[Grizwold1]

looking....

 

[odie]

I thought I had read/heard somewhere that dead yeast cells are basically "yeast nutrient" for the remaining live cells?

I'm planning a saison and I have a saison yeast slurry that's probably a year old in the fridge. Still a nice clean white/beige color in the mason jar. I do have a pack of saison standing by if I open the jar and it fails the sniff test.

 

[Bassman2003]

I would go for the fresh yeast. If anything is learned in this thread it's that old yeast that is not stored for longevity (freezing etc...) will just not perform the way we want it to. You might make something but it will not be optimal. Why waste your time and resources on a known question mark? I and others have made the mistakes and shared the experiences so other do not have to.