Reusing yeast over many generations

[GernBlanston]

Just read this from our good friend Nosybear,

http://appliedzymurgy.com/2014/10/29/an ... xperiment/

And It got me thinking. I regularly re use my yeast for about 10 generations, before tossing it and starting out fresh. This has worked well for me, as I wash and re pitch at proper rates, and if anything seems sour or nasty, I don't use it.

However, this weeks brewing involved a wlp 001 cal ale yeast about 5 generations in, And I noticed that although the last two beers were well fermented and taste fine, they have been reluctant to clear. My American Amber Ale, kegged three weeks ago and cold stored from that time is still slightly cloudy, and the Honey Blonde Ale kegged this weekend was just as cloudy going in to the keg after three weeks in the fermenter. The American Brown, which is the beer before the Amber, is crystal clear, so it was only the last two beers. Perhaps in the washing process, I collected a mutation that tends not to drop out as easy, and it has propagated to the point of being dominant, or at least plentiful enough to effect clarity. If indeed that is the case, I don't believe that this characteristic will diminish, and any future beers will be slightly hazy.

To be safe I tossed the yeast and started fresh. Something that home brewers can do easily, that commercial breweries find cost prohibitive.

Thanks Nosy for the getting my mind working in that direction. Love your blog.

 

[Ozarks Mountain Brewery]

from a brewery in another state where i once lived I talked to the head brewer and he said after 7 uses they start fresh. also Ive herd many people that work with yeast use a flame very close by when working with it just to drive away wild yest floating around

I personally don't wash yeast any more I just pull it out of the cold crashed keg after each beer, add dme and make a starter then cold crash the yeast to a slurry and store it in sealed white labs tubes at 40, always works fine but get a little nervous after 6 months of storage and start fresh

another thing I do once and a while is turn 1 new vile or packet into 6 and store it the same way, that way you get 6 first gen batches

 

[GernBlanston]

I personally don't wash yeast any more I just pull it out of the cold crashed keg after each beer, add dme and make a starter then cold crash the yeast to a slurry and store it in sealed white labs tubes at 40, always works fine but get a little nervous after 6 months of storage and start fresh

another thing I do once and a while is turn 1 new vile or packet into 6 and store it the same way, that way you get 6 first gen patches

The problem with using yeast from the keg (assuming that it is a different vessel than the primary ferment) is that you have a selected yeast that floculates and drops out last, and you don't get any of the hard working quick starting yeast that drops early, as it was left in the bottom of the fermenter. Also the reason to wash yeast is to have plenty of it on hand and never a need for a starter. My 5 gallon batch of beer is the best starter I can have. I don't store it for more than about a week, and usually not even that. If I'm not brewing for another week, I'll put off transferring from the frementer until I'm ready to wash yeast and pitch immediately. I also brew a lager ever three to four weeks, whenever the previous lager is ready to keg, that way I always have a big pitch of healthy viable yeast, without the time and expense of a starter.

I do agree with the splitting up of yeast to keep the number of generations low. less opportunity for something to go wrong.

 

[Ozarks Mountain Brewery]

I always regrow a stored batch with new dme and yeast nutrient the day before I brew just to be sure, I regularly get blow offs after switching to this set up so I use 1/2" hose to a jar of star-sans now instead of an airlock.

seems like just as much work but I have the routine down pretty good

 

[The Brew Mentor]

Someone please eject the previous poster :evil:

 

[sbaclimber]

Someone please eject the previous poster :evil:

+2 (...made 2 other SPAM posts in Good Times and Recipies :cry: )

 

[Nosybear]

Done. Post is gone, poster is warned. Cheers!

 

[rodwha]

What I've seen posted elsewhere that made a lot of sense to me was to just make a larger starter and save the excess instead of washing yeast. This way there's no particulate and nothing extreme. It seems there's less opportunity for mutations too, but I have no way of proving this.

This just made it so much easier and didn't give me more things to clean up afterward.

 

[Nosybear]

The point of the article was that the yeast split into multiple batches all followed different evolutionary paths but all ended up more or less the same place. I don't know whether that was a good place for beer yeast or not. But it does explain why some European breweries claim to have used the same yeast strain for centuries: It's adapted to their brewing methods and any mutations are selected out in favor of the "end product," their house yeast.

 

[rodwha]

In haste I did not read the article, but just the responses, and posted. I obviously need to read the article (I began, but then decided to respond first seeing that this flies in the face of what's preached). I just figured what I was told made sense compared to washing yeast.

On to the article...

 

[rodwha]

Very interesting!

I wonder if this is only true if one uses the yeast for the same recipe each time.

I noticed a mutation in my WLP-001 as I was getting much higher attenuation. Not a bad thing I don't think, but I tossed all of my liquid yeast strains as I lost track of how many times I had used them and was moving and wouldn't be brewing for a while. Knowing one strain had certainly mutated on me in a noticeable way I felt it would be good to start over and keep better track. Since then I've just been using dry yeast.