have you tried fermenting and serving from the same keg without transferring?

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have you tried fermenting and serving from the same keg without transferring?


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twd000

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I've encountered a lot of skepticism from homebrewers on this method, mostly about how it CAN'T yield good results because of yeast autolysis or some other source of off flavors.

I've been doing this for the last 15-20 batches, and I'm likely never going back to the old way.

I simply ferment 4 gallons of wort directly in a 5 gallon corny keg (actually 2 kegs so I get 8 gallons). I use a BlowTie spunding valve to maintain ~2 psi during the early phase of fermentation, then ~48 hours into active fermentation I'll increase the pressure to 15 psi. If I miss my window of opportunity, I simply force carbonate from the gas bottle as I would have done otherwise. The important thing is that there is always positive pressure and no chance of oxygen ingress after pitching yeast.

I'll let the sealed keg sit for 7-10 days at room temperature, then put it in the kegerator to chill and adjust any final carbonation level. I have a floating dip tube on my liquid line which pulls clear beer from the top of the keg, and gradually sinks with the liquid level until it pulls foam on the very last pint as it's resting on the yeast cake.

I first read about this method here on HBT; I didn't personally innovate any part of this.
Wondering how many others have tried it, and abandoned it due to problems, or made the "no-transfer" a permanent part of their process?
 
I've done it for my last several batches, and I like it. I fill the keg almost to the top, so I start with about 5 gallons. I fill it up to the part of the keg where it starts to round at the top. I add 10 drops of Fermcap and hook up a blowoff tube. There's always some blowoff because of how much I fill it, but I'm ok with that.

Once bubbling gets to about once per second (typically day 3 or 4), I remove the blowoff tube, put on the gas post, then hook up the BlowTie spunding valve. It's set at around 25 psi.

About 10 days after pitching yeast, I put it into the keezer. The next night I pull a pint. I use a floating dip tube and sometimes the first few ounces need to be tossed because some krausen got stuck. But aside from that, it's great. I have no plans to go back.
 
I have a modified version of this. I ferment in a bucket with spigot for part of the fermentation and transfer to a purged keg to finish. Spunding valve is set to 18 psi for a 54 degree ferment.

It works great with one exception. Beers take longer to fully clear.

At one point I was set on getting a pressure fermentation setup. Then I realized kegs do the job, have multiple purposes, and are less money.
 
It works very well and causes no problems, provided you work with yeast that's reasonably flocculant.

I have done it a few times, and it was great all but once. The yeast in that case didn't settle entirely on the bottom, and was floating around in a cloud perhaps a few inches up. The beer was fine until the floating dip tube reached that spot, then it started to pull hazy, then cloudy, then had a tart yeasty flavor - so it got dumped.

The only other annoyance is cleaning the keg at the end, since it's a full pile of trub (and krausen rings) to rinse out.

The freshness and simplicity of the technique makes it worthwhile. Everyone should try it at least once. You don't even need a spunding valve. Just vent the gas post to a blow-off jar, then remove it when bubbling slows way down or stops.
 
It works very well and causes no problems, provided you work with yeast that's reasonably flocculant.

I have done it a few times, and it was great all but once. The yeast in that case didn't settle entirely on the bottom, and was floating around in a cloud perhaps a few inches up. The beer was fine until the floating dip tube reached that spot, then it started to pull hazy, then cloudy, then had a tart yeasty flavor - so it got dumped.

The only other annoyance is cleaning the keg at the end, since it's a full pile of trub (and krausen rings) to rinse out.

The freshness and simplicity of the technique makes it worthwhile. Everyone should try it at least once. You don't even need a spunding valve. Just vent the gas post to a blow-off jar, then remove it when bubbling slows way down or stops.

yes there is certainly a lot of crud leftover in the keg at the end. My process is to rinse the yeast cake out with water, then invert the keg and power-wash it with HOT PBW using my sump-pump keg washer in a bucket. Spotless keg in 5 minutes and ready for Star-San and the next batch.

The only time I ran into a yeasty flavor in the keg is when I'm moving kegs around and forget to let them settle for a day or so. One time I had an Octoberfest that I stirred up by swapping in and out of the kegerator to find an open tap. Had a gross yeasty flavor for a couple days until I figured out what happened and let it settle out. DO NOT DISTURB signs on all my kegs now!
 
I have a modified version of this. I ferment in a bucket with spigot for part of the fermentation and transfer to a purged keg to finish. Spunding valve is set to 18 psi for a 54 degree ferment.

It works great with one exception. Beers take longer to fully clear.

At one point I was set on getting a pressure fermentation setup. Then I realized kegs do the job, have multiple purposes, and are less money.


yours is a good (possibly better) method as well, but I'm interested in the effect of sitting on the full yeast cake, meaning no transfer at all
 
I am filling to around an inch below the gas tube. Sometimes use ferm cap if I have it. I am finding that the fermentation is faster using a blowoff for first few days. Then pull the blowoff and spund to 25 or just pull blowoff and seal it up and let it rise. I do monitor the pressure each day. If you seal too soon the pressure can really build up. Works great and no oxygen gets in till keg kicks and I open for cleaning. I hook up the gas to serving pressure and crash in keeper.
 
I am filling to around an inch below the gas tube. Sometimes use ferm cap if I have it. I am finding that the fermentation is faster using a blowoff for first few days. Then pull the blowoff and spund to 25 or just pull blowoff and seal it up and let it rise. I do monitor the pressure each day. If you seal too soon the pressure can really build up. Works great and no oxygen gets in till keg kicks and I open for cleaning. I hook up the gas to serving pressure and crash in keeper.

no yeasty off flavors? How long have you served from a fermenting keg before it kicked?
 
I have had a few go 8 weeks. Mostly doing 10 gal batches. So the second keg in a series sits awhile. No yeasty flavors. Very little to no hop fade. It takes a few days in the keezer to clear and chill.
 
I've done my last 3 batches like this and I love it. No O2 pickup, able to cold crash with no issue, 1 vessel to clean. Top Draw system works great. I've gone 6 weeks in the keg and noticed no negative changes.
 
I’ve only done this method for one batch but I’m never going back. The resultant hop flavor and aroma is way better than I’ve ever achieved before and I used a relatively low amount of hops. Being able to reach in and hand clean the fermenter not to mention it’s stainless, is a big plus. The ability to completely remove oxygen exposure, light exposure, and contamination exposure post ferment is amazing.
 
I have had a few go 8 weeks. Mostly doing 10 gal batches. So the second keg in a series sits awhile. No yeasty flavors. Very little to no hop fade. It takes a few days in the keezer to clear and chill.

Same for me - about 8 weeks max so far with no off-flavours developing. That's with a range of different yeasts too - lager, chico, English, Belgian - all still great at the 6 to 8 week mark. I might have to stick one away for a few months to see how it goes. Fridge space is the problem though - I wouldn't leave it at room temp for a few months on the yeast.
 
Same for me - about 8 weeks max so far with no off-flavours developing. That's with a range of different yeasts too - lager, chico, English, Belgian - all still great at the 6 to 8 week mark. I might have to stick one away for a few months to see how it goes. Fridge space is the problem though - I wouldn't leave it at room temp for a few months on the yeast.


that's a good point to consider. Some of my overflow kegs are stored at "room temperature" but that's still only about 55F in my basement, which would slow down yeast activity and autolysis.

I found some info from the wine-making industry, where autolysis is actually desired

https://www.wineland.co.za/the-beauty-of-self-destruction-yeast-autolysis-in-sparkling-wine/

"Another rate limiting factor is CO2. Autolysis occurs at a slower rate when yeast is in a liquid that is saturated by carbon dioxide, such as in sparkling wine"

"Autolysis occurs upon the death of the yeast cells when the conditions of the medium in which the yeast cells must operate are such that they can no longer perform their normal functions (Castor & Vosti, 1950). This process occurs over a long period of time due to the low temperature and pH of the wine. Like any enzymatic reaction, autolysis occurs at faster rates with increasing temperatures until the temperature reaches a point at which the proteins begin to denature. The optimal temperature for yeast autolysis is approximately 60°C. However, it must occur at temperatures around 10 – 12°C, as the wine is stored at a low temperature. Also, a low pH, as found in sparkling wine, can act as an inhibitor of autolysis"
 
I use this (chill+ferment+pressure ferment+ serve in same corny) method since 4 years, and had more then 100 * 10gal (2*corny) batches. No off flavour caused by yeast cake even if it is in the keezer 4 months. But 3-4 cornies had some off flavour and it was hard to find the reason: I advice not to set the spunding valve to more then 15 psi. I know 25-30 psi 20C drops to 12 psi after cold crash, but sometimes yeast does not like too high pressure and can produce off flavour. I do slower cold crash, and hold my cornies some days before first pour after putting it into keezer.
 
I haven't tried this technique in a while, but I've got a batch of amber lager going now with WLP802. I fermented at 12 psi for two days, then began spunding with a target of 21 psi. All of this is at 58ºF.

I've usually been too late to catch enough remaining points for full carbonation. But this time, I was clearly early. Now at 5 days, it's just about finished with active fermentation, so it's been active at 21 psi for three days. I will leave it be for at least a full week though, then check FG with a picnic tap. Then into the keezer it shall go for a couple of weeks conditioning.

I hope I don't have any off flavors from the pressure, but it's an experiment, as so many brews are.
 
*bump* I just used this method (without spunding valve) on my last batch. It was an IPA and I also added the dry hop right after brewing right after yeast pitch. I never opened the keg until it kicked. But it turned out really bitter. The dry hop at yeast pitch shouldn't have caused that since there shouldn't be any isomerization at fermenting temp, right? The only other thing I can think is that I added too much bittering hops (hop shot) accidentally, but I don't think I did. I liked the idea of the beer never seeing oxygen after pitching yeast, but I probably won't dry hop at yeast pitch again. Anyone else do that and experience that?

Anyway, I have another beer going now and I plan to add the dry hop while adding some CO2 and that would be the only time oxygen could get in.
 
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I am running a little experiment too. I split a batch of german pilsner where I did half under my normal process(stepped cold ferment then move to a keg when finished at day 8 or 10) and the other half I did under pressure in a keg with a cut back dip tube. I did not purge any yeast from the fermenting half and plan to leave the beer on the yeast the entire time.

Not the best experiment as I have a few extra variables, new yeast to me, WLP925 high pressure lager and the half done in the keg I fermented warm vs a cold ferment for the other.

WLP925 seems a bit powdery so it might not have been the best yeast to keep in the keg. I also kept the keg under pressure at 10psi during the bulk of the fermentation as I was fermenting warm. Both halves finished in the same number of days.

The cold fermented half has been lagering for about 2week so I will take a quick sample of both to see how the flavors compare in a day or two and if the warm fermented wlp925 made a fast lager. I plan to continue lagering for a couple more months with the pressure keg being the last to serve. I may take a sample or two of the pressure keg before that to see if there is an issue with sitting on the yeast.
 
Interesting thread. I have my first batch on tap that I am playing with fermenting and serving from the same keg. It was a 2.5 gal batch of a Pale Ale fermented with Voss. My (newly assembled) spunding valve had a leak so I did not carbonate in the keg (I got a replacement valve that seems to work). I like the theory of saving on CO2 and maybe turning around Kveik beers in less than a week.

I have not figured out if there is a good dry hopping strategy that does not involve opening the lid. For this Pale Ale, I just added more hops to a whirlpool addition and did not dry hop.

I did get some sulfur notes from the Voss that from what I read can come from yeast stress during fermentation. I fermented it at room temp and initially the spunding valve was at 15 psi. I feel like I should have pitched more Voss if I was going to ferment at 72F. I don't think I can blame any flaws on serving from the fermenting keg. I am currently 12 days from brew day and the beer is pouring clear using a FLOTit floating dip tube.
 
I ferment in kegs for 2.5 gallon batches, never tried this. My usual method is ferment 10-14 days in the keg, close transfer to 2.5 gallon keg that is filled/purged with sanitizer. Maybe I'll try this sometime. Downside is harvesting yeast. I often times will brew 2-4 beers with the same yeast, harvested from batch to batch.
 
I did this for a bit, but did start to pick up some funky flavors as the beers aged. I still ferment in a keg with a floating dip tube, but then transfer to a serving. Takes a little more CO2, but with it imo.
 
I ferment in kegs for 2.5 gallon batches, never tried this. My usual method is ferment 10-14 days in the keg, close transfer to 2.5 gallon keg that is filled/purged with sanitizer. Maybe I'll try this sometime. Downside is harvesting yeast. I often times will brew 2-4 beers with the same yeast, harvested from batch to batch.


I'm experimenting with a new idea for harvesting yeast. Once the keg starts to build pressure, I hookup a short jumper line from the liquid (floating dip tube) to a 16-oz PET soda bottle fitted with a carbonation cap. So far so good. I figure I'm top-cropping the most active yeast, without opening the fermentation vessel.
 
I did this for a bit, but did start to pick up some funky flavors as the beers aged. I still ferment in a keg with a floating dip tube, but then transfer to a serving. Takes a little more CO2, but with it imo.
How long before you got the funky flavors? And was it any particular type of beer?
 
I did this for a bit, but did start to pick up some funky flavors as the beers aged. I still ferment in a keg with a floating dip tube, but then transfer to a serving. Takes a little more CO2, but with it imo.

I am thinking my ideal setup would be to ferment in a keg, using the CO2 from fermentation to purge a serving keg, and use a spunding valve to partially carbonate the beer. I would just then need just a little CO2 for the transfer (plus to fully carbonate and serve).
 
How long before you got the funky flavors? And was it any particular type of beer?
Mostly IPA's. Maybe 4-6 weeks. It wasn't terrible, just a little twang I was picking up. I may revist this technique just to give it another try.
 
I am thinking my ideal setup would be to ferment in a keg, using the CO2 from fermentation to purge a serving keg, and use a spunding valve to partially carbonate the beer. I would just then need just a little CO2 for the transfer (plus to fully carbonate and serve).

The new Torpedo 6 gallon kegs are great for this. I use the clear beer draft system and blowtie spunding valve....brew 5.5 gallons and then transfer to a 5 gallon corny. Next best thing to a full unitank imo.
 
I ferment in kegs for 2.5 gallon batches, never tried this. My usual method is ferment 10-14 days in the keg, close transfer to 2.5 gallon keg that is filled/purged with sanitizer. Maybe I'll try this sometime. Downside is harvesting yeast. I often times will brew 2-4 beers with the same yeast, harvested from batch to batch.

Ya have to drink the beer faster is all.

I do the same as you. Honestly, I've not served from the primary keg yet, but the only reason is because I harvest the yeast. The way timing has worked, I've just always hit it such that I was ready for the yeast about the same time I was ready for the beer in the primary to be tapped, so I would transfer to secondary and get my yeast .
 
I am thinking my ideal setup would be to ferment in a keg, using the CO2 from fermentation to purge a serving keg, and use a spunding valve to partially carbonate the beer. I would just then need just a little CO2 for the transfer (plus to fully carbonate and serve).
This is what I have been doing. For transferring, I put the fermenting keg on the counter and serving keg on the floor. Then I connect liquid to liquid and gas to gas. A short pull on the PRV of the serving keg gets the transfer going. I don't need to use any CO2 that way.
 
I’ve done this 2 times, a wheat and a stout. I fill the keg (5 gallons), have my blowtie preset to 15 psi. I put about 12” of beer line between the T and the pressure gauge just in case there is some blowoff. The pressure keeps the blowoff to a minimum. On the Stout there was a little, maybe 1” got into the line between the T and the pressure gauge. Once the pressure got up to 10 psi it receded. I rinsed the Blowtie with warm water, put it back on and left it alone for 8 days.

Then I put it in the kegerator at 11 psi and a week later I was drinking as good a beer as any other I have made. 3 months later they were as good or better that when I first tapped them.

I’m go to brew a Blonde this weekend using the same method. I’m going to pressurize it to 10 psi at the start and I doubt that there will be any blowoff.

Edit: I use a floating dip tube.
 
@CascadesBrewer you should be able to fully carbonate it in the fermenter. The pressures look alarmingly high when you use the calculator because it is all warm. Particularly with a Kveik lager ferment at 35celsius it suggests 46 psi at the end of ferment ( so ferment in a corney ) or let temp fall after the early phase to ambient and its a more manageable 24 psi. THen cold crash and it will be carbed correctly and then you can transfer as mentioned above without adding CO2 and you are good to go.
 
This is what I have been doing. For transferring, I put the fermenting keg on the counter and serving keg on the floor. Then I connect liquid to liquid and gas to gas. A short pull on the PRV of the serving keg gets the transfer going. I don't need to use any CO2 that way.

When you pull the PRV, doesn't that just result in gas transfer via the gas<--> gas connection?
 
When you pull the PRV, doesn't that just result in gas transfer via the gas<--> gas connection?
Yes. I suppose it would. I forgot to mention that I don't connect gas line to the serving keg until after the beer starts flowing.
 
definitely and interesting idea. some thoughts...

1. I'm concerned about disturbing the compact trub layer when moving to the kegerator. This would "cloud" the beer until it settles again. I guess that trub layer is purged on the first pint or two that you pull. But if that keg is disturbed than there is some wait time before you can purge and have clean beer. follow.

2. How would you use/add gelatin if so desired for clearer beer? Opening the keg introduces oxygen which is part of the reason to ferment in the keg.

3. I currently screen my kettle trub. The ferm trub is mostly yeast cake. Could I harvest yeast on the first "pull" or two?

4. How do you seal the keg during fermentation? Often the big o-ring doesn't seat until you blast it with CO2. But with a blow off tube on the gas post, the keg is unpressurized as it ferments.

5. What is the PSI rating of the PRV? Could that be used towards the end as the only airlock and also carbonate at the same time?
 
definitely and interesting idea. some thoughts...

1. I'm concerned about disturbing the compact trub layer when moving to the kegerator. This would "cloud" the beer until it settles again. I guess that trub layer is purged on the first pint or two that you pull. But if that keg is disturbed than there is some wait time before you can purge and have clean beer. follow.

2. How would you use/add gelatin if so desired for clearer beer? Opening the keg introduces oxygen which is part of the reason to ferment in the keg.

3. I currently screen my kettle trub. The ferm trub is mostly yeast cake. Could I harvest yeast on the first "pull" or two?

4. How do you seal the keg during fermentation? Often the big o-ring doesn't seat until you blast it with CO2. But with a blow off tube on the gas post, the keg is unpressurized as it ferments.

5. What is the PSI rating of the PRV? Could that be used towards the end as the only airlock and also carbonate at the same time?
1. choice of yeast, avoid low flocker or powdery ones.
2. I use a 12oz PET soda bottle with a crab cap and short gas jumper. Squeeze out air before tightening carb cap and purge a few time with CO2.
4. williams has oversize lid o-rings that help loose lids. Just need to mess with them to get a good combination.
5. I would not count on the PRV alone, better to spund or check pressure somehow.
 
definitely and interesting idea. some thoughts...

#3 - Seems like an interesting idea. I would have some concerns about clogging of the poppet at the disconnect.

#5 - I know that Morebeer sells some PRVs rated at 35PSI...and I suspect there are lower rated ones. I am not positive how much I trust the PRV to blow. Replacement PRV (35 psi) | MoreBeer
 
Get a floating dip tube, use the filter that attaches to it. I use an injector for any liquid additions so that it can be done oxygen free.
Using a conical fermentasaurus I drop most of the yeast out and can then harvest that way. Normally first 500ml or so is bits of trub and early yeast. Then you get the creamy stuff and can harvest that / save as needed.
I don't use the fermentasaurus as a routine server but start off from it sometimes or it's good for ales that don't need the keg fridge and
I can assess the hoppiness and move the hops in and out if needed.



float filter.JPGIMG-20181220-WA0002.jpegIMG_20201108_170441.jpg
 
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#3 - Seems like an interesting idea. I would have some concerns about clogging of the poppet at the disconnect.

#5 - I know that Morebeer sells some PRVs rated at 35PSI...and I suspect there are lower rated ones. I am not positive how much I trust the PRV to blow. Replacement PRV (35 psi) | MoreBeer
With regards to #3...my entire kettle gets screened thru a bucket strainer (100-200 micron). Everything, so when fermentation is done, I have a very "short" cake that appears to be most all yeast. I currently save it and the entire fermenter bucket "dregs" is about a pint total volume of beer & yeast. No other debris. Everything else goes into the keg as clean beer.

So my assumption is that using my current "kettle-to-fermenter" method as "kettle-to-keg" method would result in the same cake in the bottom of the keg. The first pint I would pour could be into a small mason jar as my yeast harvest. The next pint should be fairly clear, just residual yeast cake. Then clear beer.

but this all assumes I use the full length dip tube.


#5...I currently purge and vent my kegs at 60 psi a few times to remove O2. The PRV never bleed anything. I don't know their actual relief point but the kegs are rated for over 100 psi.
 
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