Harvesting yeast from the bottom of the keg

[Grossy]

I'm going to try and use the yeast from the bottom of the keg in my next brew.

I wanted to re-make a fantastic Wheat Ale posted by thunderworm. I brewed 10 gallons of this a month ago. In that brew I used Wyeast Kölsch 2565.

The problem is that today the HBS did not have Wyeast Kölsch 2565, they only had in inventory White Labs WLP 029 Kölsch. So I decided to use that yeast instead.

But opportunity has knocked. My wife and I just polished off the first keg of the Wheat Ale, and down there at the bottom is Wyeast Kölsch 2565!!!

I brewed up some wort for a yeast starter, chilled it, and pitched it into the bottom of the keg, then poured that into a sanitized beaker. I might have to step it up one more time before Saturday.

I will use this yeast for one 5 gallon batch.
I will use the White labs 029 for the other 5 gallon batch.

Anyone see any issues with this plan?

 

[2thGuy]

The yeast from your keg is old yeast that has probably gone dormant long ago. It will need a lot of care and probably stepped up a couple times before it is really healthy.

 

[BigFloyd]

The yeast from your keg is old yeast that has probably gone dormant long ago. It will need a lot of care and probably stepped up a couple times before it is really healthy.

I get the impression that the OP isn't talking about a corny keg, but rather his fermenter.

Most folks harvest yeast into canning jars and then do their starters in glass flasks or jars with manual or stir plate agitation. That way, you can decant the starter beer off the yeast if you want before pitching and also make sure that your wort is at the correct temp before adding yeast. I'd not make my starter in my fermenter.

 

[Grossy]

I get the impression that the OP isn't talking about a corny keg, but rather his fermenter.

Most folks harvest yeast into canning jars and then do their starters in glass flasks or jars with manual or stir plate agitation. That way, you can decant the starter beer off the yeast if you want before pitching and also make sure that your wort is at the correct temp before adding yeast. I'd not make my starter in my fermenter.

No, I am talking about the corny keg.

I have harvested yeast from the fermentor before, but in this case I am talking about the keg we just finished drinking.

The yeast is now on the stir plate in a 2000 ml beaker, about 12 hours, and it is going like gangbusters.

Now I dont know about "Old Yeast" as stated above in post #2. This yeast is 37 days old, 4 weeks in the primary fermentor, and 1 week in the corny keg.

 

[solbes]

You might have an issue with flocculation. The cells that made it all the way to your serving keg were the least flocculent ones, so you may skew your next batch that direction. I don't see a huge issue with it this time, but might not be the best way to approach it long term.

I asked a similar question about harvesting from secondary and got this answer a couple of years ago. But I never tried it. I am interested to find out your results, so post back!

 

[Grossy]

You might have an issue with flocculation. The cells that made it all the way to your serving keg were the least flocculent ones, so you may skew your next batch that direction. I don't see a huge issue with it this time, but might not be the best way to approach it long term.

I asked a similar question about harvesting from secondary and got this answer a couple of years ago. But I never tried it. I am interested to find out your results, so post back!

Thanks solbes,

But now you are forcing me to reveal that I really do not have an understanding of this issue.

Flocculation, is clumping together of the yeast. Why is this bad? or why is this an issue?

The reason I am asking for a clarification, is so that I can better answer your question later. "how did it turn out"

 

[solbes]

No problem. Flocculation is the ability of a yeast to fall out of suspension after fermenation is complete. In most cases high flocculation is a good thing as the beer clears easier and the yeast forms a nice compact yeast cake in the bottom of the fermneter. S-04 yeast is a good example of this behavior.

A case where flocculation might be bad is a yeast that should stay in suspension, like a hefeweizen or belgian wit. Having yeast in suspension is part of the style, so they are typically low flocculation yeasts by design.

In the case of Kolsch 2565, it has low flocculation properties as shipped from WYeast. I usually give my Kolsch beers 3-4 weeks in a seconary carboy between 32 and 35F, and even that is not enough sometimes to knock the yeast out of suspension. So I often use gelatin that has been dissolved and then add to the cold beer, and give a couple of weeks to speed the clearing.

So if you have a low flocculation yeast to begin with, now you might have a beer that won't clear properly. Becuase the yeast you propagated for your next batch was selected to have the lowest flocculation properties (i.e. It didn't fall out in your primary fermenter, but rather in your serving keg). Hope this makes sense

 

[BigFloyd]

Grossy, I must admit that you're the first person I've ever heard talk about harvesting yeast out of the bottom of a corny keg. Interesting.

Is there a particular reason you'd want to do this rather than harvesting the massive amount of cells from yeast cake after fermenting except out of necessity?

 

[Yuri_Rage]

Folks harvest rare/proprietary yeast strains from commercially bottle conditioned beer all the time. With a well fed starter, I see no reason why this method would be unsuccessful. In fact, it'd be nice to debunk what I think is a myth about the yeast in the keg/bottle producing less flocculant generations.

 

[Grossy]

Grossy, I must admit that you're the first person I've ever heard talk about harvesting yeast out of the bottom of a corny keg. Interesting.

Is there a particular reason you'd want to do this rather than harvesting the massive amount of cells from yeast cake after fermenting except out of necessity?

From the first post:

"I wanted to re-make a fantastic Wheat Ale posted by thunderworm. I brewed 10 gallons of this a month ago. In that brew I used Wyeast Kölsch 2565.

The problem is that today the HBS did not have Wyeast Kölsch 2565, they only had in inventory White Labs WLP 029 Kölsch. So I decided to use that yeast instead.

But opportunity has knocked. My wife and I just polished off the first keg of the Wheat Ale, and down there at the bottom is Wyeast Kölsch 2565!!!"

I did not have any washed Wyeast Kölsch 2565 yeast from the fermentor, and the HBS did not have any either.

 

[Grossy]

Folks harvest rare/proprietary yeast strains from commercially bottle conditioned beer all the time. With a well fed starter, I see no reason why this method would be unsuccessful. In fact, it'd be nice to debunk what I think is a myth about the yeast in the keg/bottle producing less flocculant generations.

Yuri,

We will see what happens, but after solbes explanation above I can see a evolutionary reason why this idea is at least credible, whether it is actual we will see in 5 weeks.

I think the theory goes like this:

The yeast that "flocculated" out of suspension, apparently are more "floctuant" that the the ones that did not.

They in turn will then pass on the lower degree of flocculation to each generation. However since yeast produce by "budding" I am not to sure how that holds up.

We will see.

 

[Yuri_Rage]

I understand the theory, I'm just not sure I buy it. I'd rather see an experiment with a more flocculant yeast strain than the one you chose, but that's not really the point of your post.

Regardless, you should be able to harvest viable yeast from the dregs of your keg.

 

[tankcrash]

I am meaning this as more of a question than an opinion.....

If you made a starter and then allowed it to settle. Wouldn't that select the more floculant strains?


So reverse the process the op created.

 

[jmf143]

That's some serious drinkin' to go through a corny in a week!

 

[Poobah58]

Folks harvest rare/proprietary yeast strains from commercially bottle conditioned beer all the time. With a well fed starter, I see no reason why this method would be unsuccessful. In fact, it'd be nice to debunk what I think is a myth about the yeast in the keg/bottle producing less flocculant generations.

What he said!

 

[Grossy]

That's some serious drinkin' to go through a corny in a week!

Ah yeah... like I said this beer was awesome. Follow the link in the OP.

 

[mcbethenstein]

Sorry to bring this thread back, but how did the next batch go? Were there any issues using the old(er) yeast?

I'm looking to rebrew a fantastic saison that was just finished at a festival. My issue is that I would order online, and wait for shipping, but its one of Wyeast's private collection yeasts… was only out from Oct-December. So the bottom of the keg is the only place I can get this yeast at all. I have it in 1/2 L starter right now, and it smells phenolic, like a early yeast starter does. I'll go through a few stages to build it up and hopefully harvest those flocculant little guys.

 

[Grossy]

There was no issue with using the yeast from the bottom of the keg.

The beer came out great.

If I were to do it again I would skip building the yeast up in stages. My second stage blew out of the flask. Made a mess. Next time I have to do this I would just make my starter the same way I have always done, add the yeast, and thats it.

 

[mcbethenstein]

Thanks, I have great activity on this stuff. I'm glad I was able to salvage some from my extremely old keg (brewed in January, kegged early Feb). I will do a second step, since I had so little to start with, and only have it in 1/2 L. Next step 2 L... Should give me enough to save some properly. I can't wait to brew this again, with a few minor tweaks and see how it ferments in the heat like it's supposed to.... Seriously, who puts out a limited release farmhouse/saison yeast in the WINTER?




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[mcbethenstein]

I skipped the second build up and pitched just the 1/2 L starter into my saison in a modified open fermentation. The following picture is of the hop drive and beautiful krausen at 12 hours since pitching. Don't worry the fermenter/bin is covered in clean towels to shield from light when I'm not taking pictures.




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