Author Topic: Headspace for a lager  (Read 2906 times)

Offline srnoel

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Headspace for a lager
« on: February 11, 2012, 05:22:01 PM »
Just looking into lagering a bit more and I was wondering, how much head space is needed when lagering.  Do lagers make a big krausen like most ales do during primary fermentation?  I know lager yeast do their fermentation at the bottom but I was thinking it will still probably krausen a fair amount.  Reason I am asking is because I was considering lagering a 2.5gallon batch in a 3gallon carboy (the biggest my current beer fridge could fit).  My guess is that it is not enough headspace but I don't know squat about lagers.

Offline tygo

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Re: Headspace for a lager
« Reply #1 on: February 11, 2012, 05:29:14 PM »
While it's actively fermenting there will be some krausen but not as much as an ale yeast, and not nearly as much as some.  So you do need some headspace but not as much.  If you fill up a carboy almost to the neck and pitch the yeast it'll still blow off.

Once it's done fermenting and you being lagering (cold storage) you don't need or want any headspace.
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Offline weithman5

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Re: Headspace for a lager
« Reply #2 on: February 11, 2012, 05:40:46 PM »
you should be fine.  i have lagered 1 gallon batches in 1 gallon juice bottles filled up to within an inch or two and just a stopper and airlock. no issues what so ever.  tomorrow will be doing 2 gallons in a bucket that holds probably 2.25 gallons. i expect no issue.  just remember to keep the temp down
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Offline denny

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Re: Headspace for a lager
« Reply #3 on: February 11, 2012, 06:16:35 PM »
Lagers don't really ferment on the bottom.  The latest BYO talks about that in the article on the origin of lager yeast.
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Offline euge

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Re: Headspace for a lager
« Reply #4 on: February 11, 2012, 06:21:11 PM »
Lagers don't really ferment on the bottom.  The latest BYO talks about that in the article on the origin of lager yeast.

I've long suspected this. Care to elaborate?
The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman

Offline hopfenundmalz

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Re: Headspace for a lager
« Reply #5 on: February 11, 2012, 07:02:49 PM »
Lagers don't really ferment on the bottom.  The latest BYO talks about that in the article on the origin of lager yeast.

I've long suspected this. Care to elaborate?

The yeast is throughout the beer.  Less is in the krauesen than for an ale. 
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Offline euge

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Re: Headspace for a lager
« Reply #6 on: February 11, 2012, 08:18:04 PM »
Lagers don't really ferment on the bottom.  The latest BYO talks about that in the article on the origin of lager yeast.

I've long suspected this. Care to elaborate?

The yeast is throughout the beer.  Less is in the krauesen than for an ale. 


And fermenting cold produces a lengthier and less of a vigorous fermentation therefore less krausen too. At least thats how I see it.

The misconception that the yeast ferment on the bottom comes from "if it ain't on top then it must be on the bottom?"


The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman

Offline tschmidlin

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Re: Headspace for a lager
« Reply #7 on: February 12, 2012, 01:49:07 AM »
The misconception that the yeast ferment on the bottom comes from "if it ain't on top then it must be on the bottom?"
As far as I know.  If you've used a lot of yeast and watched you'll notice that not all ale yeast make a large foamy head during ferment, and lager yeast don't fall to the bottom right away and do their work there.  It's BS, and has always bugged me - although less than other things. ;)
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Offline bluesman

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Re: Headspace for a lager
« Reply #8 on: February 12, 2012, 08:26:13 AM »
I brew a Bopils every year in the late winter and I use WLP800. Ironically, I get a relatively large and dense krausen layer. The krausen is thicker than most of the ale yeast (i.e. WLP001 or WY1056). It's a bright white krausen with some off-white colors mixed in. It almost looks like a whipped cream type consistency. I've often thought about scooping some of it off the top and saving it for krausening the beer after fermentation.
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Offline weithman5

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Re: Headspace for a lager
« Reply #9 on: February 12, 2012, 08:42:30 AM »
i just made a starter with 830.  did not use a stir plate.  although it does appear throughout, there is still a large amount of yeast settle out on he bottom. you can watch and see them kind of form buds that separate and drift to the top then slowly fan out and settle.
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Offline thomasbarnes

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Re: Headspace for a lager
« Reply #10 on: February 13, 2012, 11:43:22 PM »
Lagers don't really ferment on the bottom.  The latest BYO talks about that in the article on the origin of lager yeast.

I've long suspected this. Care to elaborate?

Any yeast ferments when it's in suspension. Once it drops out of suspension it goes dormant pretty quickly.

The terms "top fermenting" vs. "bottom fermenting" are technically misnomers. It's more correct to call them "top-cropped" and "bottom-cropped" yeasts.

Historically, the barm (AKA krausen) on top of fermenting ales was scraped off (or allowed to overflow into another container and then collected) and pitched into a new batch of beer, hence "top cropped" or "top fermenting." Some of these strains (e.g., Pride of Ringwood) are noted for being "powdery" in that they flocc poorly and must be removed with finings or filtration.

By contrast, lagers were brewed using yeast cake left in the bottom of the lagering vessel, hence "bottom cropped" or "bottom fermenting." This favored strains which flocculated well and could survive long conditioning times and cold temperatures.

Offline jeffy

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Re: Headspace for a lager
« Reply #11 on: February 14, 2012, 04:27:53 AM »
Lagers don't really ferment on the bottom.  The latest BYO talks about that in the article on the origin of lager yeast.

I've long suspected this. Care to elaborate?

Any yeast ferments when it's in suspension. Once it drops out of suspension it goes dormant pretty quickly.

The terms "top fermenting" vs. "bottom fermenting" are technically misnomers. It's more correct to call them "top-cropped" and "bottom-cropped" yeasts.

Historically, the barm (AKA krausen) on top of fermenting ales was scraped off (or allowed to overflow into another container and then collected) and pitched into a new batch of beer, hence "top cropped" or "top fermenting." Some of these strains (e.g., Pride of Ringwood) are noted for being "powdery" in that they flocc poorly and must be removed with finings or filtration.

By contrast, lagers were brewed using yeast cake left in the bottom of the lagering vessel, hence "bottom cropped" or "bottom fermenting." This favored strains which flocculated well and could survive long conditioning times and cold temperatures.
I think you meant Ringwood yeast.  Pride of Ringwood is a hop variety.
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Offline morticaixavier

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Re: Headspace for a lager
« Reply #12 on: February 14, 2012, 08:15:33 AM »
The misconception that the yeast ferment on the bottom comes from "if it ain't on top then it must be on the bottom?"
As far as I know.  If you've used a lot of yeast and watched you'll notice that not all ale yeast make a large foamy head during ferment, and lager yeast don't fall to the bottom right away and do their work there.  It's BS, and has always bugged me - although less than other things. ;)

you mean like the wet hopped Black Pale Ale I brewed with bottom fermenting yeast? I did a secondary fermentation too!  ;D
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Offline euge

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Re: Headspace for a lager
« Reply #13 on: February 14, 2012, 08:47:39 AM »
Great answers! You've confirmed my extrapolation based on my own experiences and observations.
The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman

Offline richardt

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Re: Headspace for a lager
« Reply #14 on: February 14, 2012, 11:43:18 AM »
Good to know.  Intuition suggests that yeast cells actively producing CO2 would be more bouyant than yeast cells which are not producing CO2.  Similarly, ale yeast (at warmer temps) are more metabolically active and produce more CO2 in a shorter period of time, so it stands to reason that, relative to lager yeast, more foaming would occur, more headspace would be required (unless antifoam agents are used), and that more ale yeast would be found in the krausen.

The fermentation temperature has a huge effect on yeast cell metabolism and it is the sugar metabolism rate (and CO2 production rate) that dictates the relative amount and position of the yeast cells within the fermentor.  Since the metabolism is slower for lager yeast, you don't need as much headspace for your fermentor.

Purists will still say that lager yeasts (S. pastorianus, nee S. carlsbergensis) can fully metabolize melbiose, raffinose, etc. and are genetically distinct from ale yeast (S. cervesiae).  Other lager yeast strains include S. bayanus and S. uvarum.  Anyone who has watched the hypnotic effects of active fermentation (of any yeast type) in a clear fermentor will agree that there's a lot of movement during fermentation, so it's probably time to stop using the inaccurate terms "top-fermenting" and "bottom-fermenting."