Viability of 7th Gen Yeast Slurry?

[Apoxbrew]

Anyone have thoughts (even ballpark) on the viability of a 7th gen yeast slurry I picked up from a local brewery yesterday?

Just trying to determine pitch amount with mr. malty and i'm not sure what to put in for viability. Have 80% plugged in right now but maybe not correct?

I know you can't get a true idea without a count... just looking for a ballpark here.

 

[Nanobru]

More important than viability is cleanliness of the yeast, and the flavor profile that the yeast will create. As the yeast is reused (regenerated) it has the potential to become infected with wild yeasts and bacteria. Later generations do not perform the same way as previous generations, and the flavor and flocculation will not be the same as intended. For these reasons, breweries dump the yeast and start with new yeast purchased from a lab after 6-8 generations. In my opinion (which is debated) the risk is not the worth the expense of a new pitch, unless you do not have access to fresh yeast.

 

[Calder]

7th generation yeast is just as viable as 1st generation yeast.

There are two things to consider:

1) Cleanliness. You can get wild yeasts starting to compete with the main yeast. They still make beer. Getting the yeast from a brewery, I would think it would be pretty clean and would not have an issue with it. I have used yeast up to about 15 generations before.

2) Mutation. With each generation, the yeast changes slightly to adjust to it's environment. This is the reason Breweries only use yeast a certain number of generations, because they have to produce a consistent product. Depending what you want from the yeast, a seventh generation yeast may produce a better product than the first generation yeast; it may attenuate more or less, may flocculate more or less, may be fruitier or drier, etc.

Give it a go. You can assume it was fresh when you got it with very little trub.

 

[Apoxbrew]

thanks calder!! to be safe i'll plug it in as 80% viable in order to get the milliliters of slurry to pitch off of mr malty.

thanks again!

 

[lamppa]

Jamil speaks of yeast hitting its sweet spot after so many gens. Like 9 or something with one he had.

I never go over 3 cuz im scared.

 

[TarheelBrew13]

People get too concerned with how old there yeast is in my opinion.

Its all about yeast management. How well did they take care of there yeast. Some breweries have used the same yeast there entire time in business. Charlie Papazian reused his yeast over and over and over and over for both ales and lagers and now we have WLP862 Cry Havoc. And that's a very fine yeast.

And, its not like White Labs is over in there lab making new yeast from Carbon. They are just propagating yeast too. I'm over simplifying it but if yeast really mutated that fast places like Sam Smith wouldn't be able to make such an absolutely amazing Oatmeal Stout. Check out the wiki page for Sam Smith:

http://en.wikipedia.org/wiki/Samuel_Smith_Brewery

and you'll see, "Brewing water for ales and stouts is still drawn from the original 85 ft (26 m) well, sunk when the site was established in 1758, and the yeast used in the fermentation process is of a strain that has been used continuously since approximately 1900 - one of the oldest unchanged strains in the country.[3]"

Now I don't know how many generations that yeast has lasted but I'm pretty sure they are gonna be further along than 7 if they've been using the same yeast for over 100 years.

If I could get my hands on free brewery yeast, I'd be all over it. As for viability, I would say 80% is a fair approximation. In truth its probably even above that. Most of the breweries I've visited keep their yeast in a small conical that lives in the walkin. When they need yeast for a pitch, they draw it off the fermenter and warm only that portion of the yeast. Breweries can't afford long lag times, so they usually take care to maintain there yeast.

Also, Jamil Zanishasheff is not a biologist or chemist of any kind, he has a degree in software engineering. Chris White is a biochemist but then he has a reason for telling you not to reuse your yeast.

 

[Calder]

People get too concerned with how old there yeast is in my opinion.

Its all about yeast management. How well did they take care of there yeast. Some breweries have used the same yeast there entire time in business. Charlie Papazian reused his yeast over and over and over and over for both ales and lagers and now we have WLP862 Cry Havoc. And that's a very fine yeast.

And, its not like White Labs is over in there lab making new yeast from Carbon. They are just propagating yeast too. I'm over simplifying it but if yeast really mutated that fast places like Sam Smith wouldn't be able to make such an absolutely amazing Oatmeal Stout. Check out the wiki page for Sam Smith:

http://en.wikipedia.org/wiki/Samuel_Smith_Brewery

and you'll see, "Brewing water for ales and stouts is still drawn from the original 85 ft (26 m) well, sunk when the site was established in 1758, and the yeast used in the fermentation process is of a strain that has been used continuously since approximately 1900 - one of the oldest unchanged strains in the country.[3]"

Now I don't know how many generations that yeast has lasted but I'm pretty sure they are gonna be further along than 7 if they've been using the same yeast for over 100 years.

If I could get my hands on free brewery yeast, I'd be all over it. As for viability, I would say 80% is a fair approximation. In truth its probably even above that. Most of the breweries I've visited keep their yeast in a small conical that lives in the walkin. When they need yeast for a pitch, they draw it off the fermenter and warm only that portion of the yeast. Breweries can't afford long lag times, so they usually take care to maintain there yeast.

Also, Jamil Zanishasheff is not a biologist or chemist of any kind, he has a degree in software engineering. Chris White is a biochemist but then he has a reason for telling you not to reuse your yeast.

Probably the bigger concern is character selection, due to your process, rather than mutation. And yes, it does happen. I recently had WLP022 (Essex English yeast) start giving me 95%+ attenuation. Happened 2 generations in a row. I pulled some new yeast out of the freezer and it's back to running around 80%. I also had a PacMan strain that started getting less attenuative over time. I retired that one recently.

 

[mccabedoug]

As stated previously, assuming your sanitation is fine, there is nothing wrong with using a multi-generation yeast. I've gone up to 5 - 6 without issues.

For me, the reason I don't get to high number generations of yeast is by the time I get to that number, I am usually ready for a new style of beer. In other words, I am sick of the style of beer that the yeast tends to produce and I am ready for something new. Yeast still works like a champ.