Re using yeast from fermented keg

[scogan]

I am fermenting and serving from the same corny using a floating dip tube .When you get to the dregs does anyone just throw a fresh batch of wort in on top of all the trub and set off fermenting again ? Are there pitfalls ? I would have to fish my ispindel and dry hop bag out with a serilised pair of tongs first !

 

[Jack Arandir]

You maniac you!

Sure go ahead. If you have good sanitation and healthy yeast it should turn out quite well. Old trub and dead yeast can contribute unpleasant flavors, so that would be your pitfall. But try it and see how it goes.

 

[Zambezi Special]

I do this in my fermentor and haven't noticed any adverse effect.
I just pour wort on the trub.

 

[IslandLizard]

Are there pitfalls

You may risk some "over pitching" as yeast grows her population 4-5 times during fermentation. Maybe swirl up that yeast cake and dump half of it out?
I also echo what @Jack Arandir said.

 

[odie]

I do this frequently. When the keg blows...or the beer gets cloudy and I know it's near the end...

I will shake up the keg good, get a mason jar or two, and tap the last bit of whatever is in the bottom. Instant yeast harvest and it cuts the remaining keg yeast down to a normal pitch amount.

keep empty-ish keg cold.

make a fresh batch of same/similar beer.

open keg, if smells ok, dump that wort in and let her rip.

CAVEAT...I do fully strain all my kettle (100-200 micron) so I have nothing but extra clean wort, and thus nothing but extra clean yeast cake in the keg.

 

[scogan]

I do this frequently. When the keg blows...or the beer gets cloudy and I know it's near the end...

I will shake up the keg good, get a mason jar or two, and tap the last bit of whatever is in the bottom. Instant yeast harvest and it cuts the remaining keg yeast down to a normal pitch amount.

keep empty-ish keg cold.

make a fresh batch of same/similar beer.

open keg, if smells ok, dump that wort in and let her rip.

CAVEAT...I do fully strain all my kettle (100-200 micron) so I have nothing but extra clean wort, and thus nothing but extra clean yeast cake in the keg.

Thats helpful thanks ,what do you think about the fact that even though I will lift out the dry hop bag, there will be some hop debris probably ?

 

[odie]

Thats helpful thanks ,what do you think about the fact that even though I will lift out the dry hop bag, there will be some hop debris probably ?

not that much debris I guess. plus, when you are re-fermenting in the same keg you "should" be doing another of the same recipe or something very similar.

 

[Yesfan]

I did this with a recent double batch. The second go around, I had activity in just a couple of hours! That might have been an overpitch as mentioned by Island Lizard, but the beer turned around quick and tasted good.

Similar topic on fermenting in a keg. If you're going to pitch a second batch on the first batch's yeast cake, does it matter if the first batch was a pressure fermentation? What about if batch one was a non-pressured fermentation but batch two will be pressure fermented?

 

[beersk]

Similar topic on fermenting in a keg. If you're going to pitch a second batch on the first batch's yeast cake, does it matter if the first batch was a pressure fermentation? What about if batch one was a non-pressured fermentation but batch two will be pressure fermented?

I would say it probably doesn't matter. The pressure won't hurt the yeast any and give it fresh wort, they'll get to work.

I've been pressure fermenting for a while now, but haven't really done much of the ferment-and-serve in one keg thing. The biggest downside is harvesting yeast. But if folks are saying you can ferment a beer for 2 weeks, carbonate while fermenting under pressure, put it in the kegerator, tap it 2 weeks later, and have it last 4-8 weeks on tap, for a total of 8-12 weeks in the keg, THEN re-pitch onto that yeast? That's something I never ever would've thought possible. Not sure why, now that I think of it...but yeah, that's the biggest limitation. It otherwise sounds like an awesome way to brew.

 

[odie]

But if folks are saying you can ferment a beer for 2 weeks, carbonate while fermenting under pressure, put it in the kegerator, tap it 2 weeks later, and have it last 4-8 weeks on tap, for a total of 8-12 weeks in the keg, THEN re-pitch onto that yeast?

I do it all the time.

just started a year or two ago. Been great so far.

 

[beersk]

I do it all the time.

just started a year or two ago. Been great so far.

Then again, you've said you are essentially filtering your wort going into the fermenter. I am not doing this, I don't pay special attention to trub going in. I don't think that matters particularly, honestly. Still, pretty cool knowing you can do that. I might play around with this a little, though, lately, with my 5 gallon batches, what I'll do is ferment 2 weeks, rack to a keg on brew day, rack new wort in, and do this probably 4 times. That has also been pretty awesome, especially for lagers. I'm not sure how wild I am about the idea of waiting 2-3 months before being able to use a particular yeast again. But this would also make it more possible to keep multiple yeasts going at the same time, I suppose...

 

[scogan]

I did this with a recent double batch. The second go around, I had activity in just a couple of hours! That might have been an overpitch as mentioned by Island Lizard, but the beer turned around quick and tasted good.

Similar topic on fermenting in a keg. If you're going to pitch a second batch on the first batch's yeast cake, does it matter if the first batch was a pressure fermentation? What about if batch one was a non-pressured fermentation but batch two will be pressure fermented?

Just started it off today , I didn`t remove any trub just added the fresh wort straight in, normally this recipe takes 24 hrs to start, this time it was underway in less than an hour .I will post how it turns out ,fingers crossed !

 

[odie]

I didn`t remove any trub just added the fresh wort straight in, normally this recipe takes 24 hrs to start, this time it was underway in less than an hour .

you pitched onto a full yeast cake. that's a "super pitch" it sounds like.

what I do...

when the keg is empty or floating dip tube starts to pick up trub and is about to blow empty, I will pull the keg. I then shake it up pretty good and tap the "dregs" out into a mason jar to harvest/save the yeast for future use.

Whatever yeast/trub that remains in the keg is plenty to start another batch if I'm wanting to do another same/similar beer.

If not quite ready, I'll toss the keg in cold storage until time to brew, within a couple weeks or so.

So now what I have is an empty keg with yeast ready to go...plus a jar of harvested yeast for later (weeks, or months, perhaps a year)

 

[scogan]

you pitched onto a full yeast cake. that's a "super pitch" it sounds like.

what I do...

when the keg is empty or floating dip tube starts to pick up trub and is about to blow empty, I will pull the keg. I then shake it up pretty good and tap the "dregs" out into a mason jar to harvest/save the yeast for future use.

Whatever yeast/trub that remains in the keg is plenty to start another batch if I'm wanting to do another same/similar beer.

If not quite ready, I'll toss the keg in cold storage until time to brew, within a couple weeks or so.

So now what I have is an empty keg with yeast ready to go...plus a jar of harvested yeast for later (weeks, or months, perhaps a year)

That’s good advice , I think your phrase super pitch is apt ,as I am currently cleaning Krausen out of my gas disconnect to keep my blow off tube working ,which is generally said to be unusual for corny fermenters,especially on a 15 litre (4gallon) batch at 20C ! Btw, How do you tap the residual yeast , tip it out through the top ?

 

[odie]

How do you tap the residual yeast

ok, when you ferment and serve in the SAME keg, all the yeast will fall and pack down on the bottom.

REGULAR DIP TUBE: If you are using the regular dip tube, the first pint or two will blow a lot of that yeast out. So you tap that yeast into a mason jar BEFORE drinking the keg and save it for another day. After a pint or two, the area around the dip tube will be clear and you can enjoy clear beer. When the keg finishes, there is still some yeast cake stuck to the bottom, but not around the tube. Not enough to harvest but enough to dump fresh wort on it. Just brew a similar beer and dump it in. No cleaning necessary.

FLOATING DIP TUBE: if you are using a floating dip tube. All the yeast stays compacted at the bottom as you drink the beer. So you tap that yeast AFTER drinking the keg. At the very end, you will probably get a yeasty pint, so that is your "warning". STOP DRINKING, remove the keg and give it a nice shake to stir up the yeast cake. tap the yeast into a mason jar and save it for another day. there will still be plenty in the keg to dump fresh wort onto.

 

[odie]

OH....an important point...

I do screen (100-200 micron) all my wort from the kettle BEFORE it goes into the keg. I have little to no trub or hops material and basically a pure, clean yeast cake harvest.

I do not have to "wash" the yeast.

Note how clean and white that yeast cake is in the previous post.

You don't have to screen the wort but I think the results speak for itself.

 

[scogan]

ok, when you ferment and serve in the SAME keg, all the yeast will fall and pack down on the bottom.

REGULAR DIP TUBE: If you are using the regular dip tube, the first pint or two will blow a lot of that yeast out. So you tap that yeast into a mason jar BEFORE drinking the keg and save it for another day. After a pint or two, the area around the dip tube will be clear and you can enjoy clear beer. When the keg finishes, there is still some yeast cake stuck to the bottom, but not around the tube. Not enough to harvest but enough to dump fresh wort on it. Just brew a similar beer and dump it in. No cleaning necessary.

FLOATING DIP TUBE: if you are using a floating dip tube. All the yeast stays compacted at the bottom as you drink the beer. So you tap that yeast AFTER drinking the keg. At the very end, you will probably get a yeasty pint, so that is your "warning". STOP DRINKING, remove the keg and give it a nice shake to stir up the yeast cake. tap the yeast into a mason jar and save it for another day. there will still be plenty in the keg to dump fresh wort onto.

View attachment 813896View attachment 813897

Thank you .I have only tried floating dip tube so far .The clear beer just stopped suddenly so I had no way to harvest .Guess I could have thrown some sterile water in and repressurised again .I am kind of thinking that seeing as I have to open the keg and pull out my ispindel and maybe a hop bag too , I might just ladel some of the trub out.

 

[Yesfan]

@odie Three likes in one day. That's a turkey in bowling....


I definitely apply this technique on my next brew day.

 

[odie]

Thank you .I have only tried floating dip tube so far .The clear beer just stopped suddenly so I had no way to harvest .Guess I could have thrown some sterile water in and repressurised again .I am kind of thinking that seeing as I have to open the keg and pull out my ispindel and maybe a hop bag too , I might just ladel some of the trub out.

so you have the floating dip tube. re-read second part of post #15.

The clear beer stopped which means you are at the end of the keg, or very near the end.

So get you a mason jar and tap the last of the keg into it. That is your yeast harvest.

If you are planning another batch of the same or similar, just leave the keg sealed and cold. When you are done brewing, you can then open the keg and fish out the hop sack and dump the fresh wort in.

Or you can just clean the keg and use the yeast you just tapped out into the mason jar.

 

[scogan]

so you have the floating dip tube. re-read second part of post #15.

The clear beer stopped which means you are at the end of the keg, or very near the end.

So get you a mason jar and tap the last of the keg into it. That is your yeast harvest.

If you are planning another batch of the same or similar, just leave the keg sealed and cold. When you are done brewing, you can then open the keg and fish out the hop sack and dump the fresh wort in.

Or you can just clean the keg and use the yeast you just tapped out into the mason jar.

I have read the post, but my keg went dry with no warning, so I had clear beer ,then nothing came out but gas so no way to harvest .

 

[odie]

I have read the post, but my keg went dry with no warning, so I had clear beer ,then nothing came out but gas so no way to harvest .

Well, sometimes my kegs go "dry" without warning. I'm pulling nice beer and bam...foam and gas.

Different yeasts will drop and pack tighter than others. I haven't kept notes but it seems my Czech pils is clean to the end. I have never gotten a yeast harvest, I just re-pitch into the keg.

Saison and ales and Kolsch (ale yeast) I've gotten some good harvests.

I guess it "seems" ale yeasts don't drop and pack as tight as lager yeasts.

Not every time I get a "warning". It's hit or miss.

If the keg just went dry, skip harvest and proceed directly to fresh wort pitch.

Some times when the keg seems "dry", I can still pull it, shake it up a little and pop a small mason jar sample of yeast out for saving. There will still be sufficient yeast in the keg for immediate re-pitch.

brewing, is an art, not a science. just go with the flow.

 

[scogan]

"Go with the flow" - quite apt !!

 

[Yesfan]

Well, sometimes my kegs go "dry" without warning. I'm pulling nice beer and bam...foam and gas.

Different yeasts will drop and pack tighter than others. I haven't kept notes but it seems my Czech pils is clean to the end. I have never gotten a yeast harvest, I just re-pitch into the keg.

Saison and ales and Kolsch (ale yeast) I've gotten some good harvests.

I guess it "seems" ale yeasts don't drop and pack as tight as lager yeasts.

Not every time I get a "warning". It's hit or miss.

If the keg just went dry, skip harvest and proceed directly to fresh wort pitch.

Some times when the keg seems "dry", I can still pull it, shake it up a little and pop a small mason jar sample of yeast out for saving. There will still be sufficient yeast in the keg for immediate re-pitch.

brewing, is an art, not a science. just go with the flow.

How many repitches to the yeast cake do you do in a keg before breaking it down all the way to clean it?

 

[odie]

have not decided yet. I've gotten maybe 3-4 on one.

I have 7 taps and 15? kegs. And with harvests saved in jars I can do a break down but still keep that yeast perpetuating.

I guess until I have a batch taste like crap. Or the keg stinks when I open the lid to pitch.

I've heard of guys going 10 plus generations.

 

[Yesfan]

Wow, 10?

I can't remember the YTer's name, but there's one video where this homebrewer does an x number of pitches into the same carboy (or maybe he went a year without cleaning it, can't remember). It looked, well,.....nasty. IIRC, I don't think he ever got an infection.

I have a larger keg I use for fermenting that won't fit in my kegerator. How long do you think a cake could go between batches (if kept sealed/pressurized) if stored at room temp? Temp is in the mid 60s.