Racking - Headspace?

[hughman666]

ok so im going to rack my brew tomorrow after 7 days in primary to another 23L fermenter. this will be done via tubing connected to the tap of the primary and running into the base of the secondary to minimise splashing etc

my question is:

is it a problem that there will be headspace in the secondary fermenter?

it has an airlock etc, and will be sealed for the duration. i have seen threads where people say no headspace is essential, others say that racking to another 23L fermenter is fine.

would it be better if fermentation is still kicking along slowly when racking so that the secondary fermenter's headspace would be taken up by the CO2?

btw, this is for a lager.

cheers! :chug:

 

[stephen]

I add about three teaspoons of sugar dissolved in about half a cup of hot water when I rack. This small amount gets fermented and provides a CO2 gas layer on top of the wort.

Hope this helps. Others may have different views on this.

Steve

 

[muga]

I always find that when I rack my beer after it has stopped fermenting that it will have one little burst for half a day where it will bubble every 20 seconds or so.. it's enough to push all the oxygen out.

 

[stephen]

G'day Muga

I've heard of that technique before and upon research came across two schools of thought regarding this.

First was, the act of racking stirs up settled "stuff" from the primary and these a drawn out into the secondary. The agitation of the combined fermantables and the yeast picks the fermentation up again.

The second was, the act of racking provides a certain amount of agitation which, akin to shaking a can of softdrink , releases the CO2 disolved in the wort and this is what is released through the airlock.

I decided to err on the side of safety and go with the couple of teaspoons of sugar into the secondary when I rack as I know that they should be fermented to poduce the CO2 to provide that layer of protection.

Steve

 

[Simon W]

I'd say its probably a combination of both those Steve, plus, a slight increase in the temperature while moving the brew around will also release some dissolved CO2.

I've just relied on the escape of dissolved gas, never had a problem thus far.

Edit:
Also, A certain amount of air will have a certain amount of airborne dust/bacteria/wildyeasts etc. These airbornes will eventually settle on the surface of the brew in the still air of the fermenter. No amount of CO2 will stop this happening, unless theres a fair bit of moving air to keep that stuff airborne. Even then, in moving air, all that stuff would eventually come into contact with the brew.
So maybe the point of having as little headspace as possible is an attempt to reduce the number of airborne contaminants settling on the surface, decreasing the possibility of infection? Halve the headspace, halve the chance of infection?

I dunno, just a thought.

 

[Keith the Beer Guy]

Hi guys,

I'm gonna to take the opportunity to put people to sleep with some Chemistry.

Muga the reason you observe a brief increase in activity (bubbling) after racking is because you have disturbed the equilibrium between the dissolved CO2 in the beer and the CO2 in the headspace above the beer. After racking the beer a new equilibrium is established and this happens by CO2 coming out of solution.

This is like pouring a beer from a bottle. When the lid was on the bottle, the CO2 was dissolved in the beer. After you crack the seal, the beer starts to fizz. This is the magic of CO2 establishing a new equilibrium and in the process making my beer nice and tasty.

My own experience is that this activity is more than enough to minimise problems that come about from O2 oxidising beer. Expecially if you rack just when the rush of primary fermentation is starting to wind down.

Please note that the above paragraph is not an original thought and comes from the wisdom of Palmer, "How to Brew" aka "The Bible" 2nd Ed.; p 105. Palmer also advises against racking to plastic fermenters because they are permeable to oxygen. (However; I have not observed any staling problems when using plastic secondaries.)

Cheers,

Keith

 

[Finite]

If they are plastic and food grade and you are only racking for a week it shouldnt be a problem. Extended periods like 2+ weeks should be racked in a 20L glass carboy.

 

[normell]

If they are plastic and food grade and you are only racking for a week it shouldnt be a problem. Extended periods like 2+ weeks should be racked in a 20L glass carboy.

[post="107913"][/post]​

Any reason for this statement :blink:
Have racked into food grade plastic for 4-5 weeks at a time, with out any problems.

Normell

 

[Mr Bond]

If they are plastic and food grade and you are only racking for a week it shouldnt be a problem. Extended periods like 2+ weeks should be racked in a 20L glass carboy.

[post="107913"][/post]​

Any reason for this statement :blink:
Have racked into food grade plastic for 4-5 weeks at a time, with out any problems.

Normell

[post="107916"][/post]​

gotta say I've never had any probs either,It just seems to be some american foible that is perpetuated on US brew sites.

 

[Ross]

If they are plastic and food grade and you are only racking for a week it shouldnt be a problem. Extended periods like 2+ weeks should be racked in a 20L glass carboy.

[post="107913"][/post]​

What a load of nonsense... Sorry Finite

 

[Finite]

Oh well thats good news for me then. Ive read that the plastic can be oxygen permiable after a while and that you should use it for too long.

Im sorry that just what i read i didnt make it up...ill try and find the link

 

[pint of lager]

You are right Finite, plastic is permeable.

There was a very good thread about this some time back, if you do a search on permeable or permeability, you should be able to dig it up. The end result was that for short term, plastic is fine.

The same goes for plastic PET bottles. I have seen unopened soft drink bottles that are flat when opened. So the CO2 has gotten out and there is just as much chance for oxygen to have gotten in. But these bottles are at least a year old.

Long term secondarying and long term bottling, I do in SS or glass. Short term plastic. The length of the short term would be dependant on many variables, the type of plastic, thickness, pressures etc, but 3 months should be fine.

 

[Pumpy]

If they are plastic and food grade and you are only racking for a week it shouldnt be a problem. Extended periods like 2+ weeks should be racked in a 20L glass carboy.

[post="107913"][/post]​

What a load of nonsense... Sorry Finite

[post="107922"][/post]​

Ross do you mean "poppycock" ol' Pommy slang

Pumpy

 

[Finite]

It is important to minimize the amount of headspace in the secondary fermentor to minimize the exposure to oxygen until the headspace can be purged by the still-fermenting beer. For this reason, plastic buckets do not make good secondary fermentors unless the beer is transferred just as the primary phase is starting to slow and is still bubbling steadily. Five gallon glass carboys make the best secondary fermentors. Plastic carboys do not work well because they are too oxygen permeable, causing staling.

From: http://www.howtobrew.com/section1/chapter8-4.html

I have also read this in other places which mentions trying to reduce the time of how long its in plastic secondary's for. Again this is just what I have read and doesnt necessary mean it is true.

 

[Ross]

It is important to minimize the amount of headspace in the secondary fermentor to minimize the exposure to oxygen until the headspace can be purged by the still-fermenting beer. For this reason, plastic buckets do not make good secondary fermentors unless the beer is transferred just as the primary phase is starting to slow and is still bubbling steadily. Five gallon glass carboys make the best secondary fermentors. Plastic carboys do not work well because they are too oxygen permeable, causing staling.

From: http://www.howtobrew.com/section1/chapter8-4.html

I have also read this in other places which mentions trying to reduce the time of how long its in plastic secondary's for. Again this is just what I have read and doesnt necessary mean it is true.

[post="107952"][/post]​

Not denying that plastic is oxygen permable - It was your statement that beer shouldn't be kept in a plastic secondary for more than 2 weeks that I questioned...

cheers Ross

 

[Finite]

ah yeh sorry when i read back i realised that I didnt mention why i said that. what I should have wrote is.

'I have read you probably shouldnt leave beer in a plastic secondary for more that 2-3 weeks as it is oxygen permiable'

Then again i have read that people have left it in a secondary for 2 months and its been fine....ill stick with plastic. I think there is a stage where u have to ask "am i being anal?"

 

[Ross]

ah yeh sorry when i read back i realised that I didnt mention why i said that. what I should have wrote is.

'I have read you probably shouldnt leave beer in a plastic secondary for more that 2-3 weeks as it is oxygen permiable'

Then again i have read that people have left it in a secondary for 2 months and its been fine....ill stick with plastic. I think there is a stage where u have to ask "am i being anal?"

[post="107956"][/post]​

Finite,

Trust me, a beer left in a plastic secondary for 2 or 3 months will not suffer any noticable affect from the plastic being oxygen permiable...

cheers Ross

 

[sam]

Carboys are a PITA. Syphoning out of them is really quite annoying. Plastic with taps are far easier to use, and as for use of them as secondary fermenters, they work really well. Don't leave beer in plastic for extended periods of time, and all will be well.

I'm glad the thing for glass carboys in the US hasn't become embedded in Aus.

I feel that simply transfering from one fermenter to another causes a decent amount of CO2 to come out of solution (due to temp and gentle agitation) and fill the headspace of the fermenter, forcing out air.

This will work better in a container with less headspace, but I think 30L drums are still fine for it.

If you've got kegs, and are still concerned, you can whack some CO2 from your bottle in the drum.

Glass carboys have their place, but in general brewing, they aren't really necessary.

Cheers,

Sam

 

[WildaYeast]

Hi there,

First post. Be kind!

I think my question fits reasonably into this thread. I have transferred my brew into a secondary plastic fermenter. It is about 23L, but because it expands a bit from the pressure of the liquid, I have a little headspace. I added about 2tsp of sugar and finings when I transferred from my primary, a little over a week ago. I started with a bung and air lock, but then decided I wasn't getting a lot of activity so I would just cap it. Before sealing down the cap tight, I gave it a squeeze to expel all the air, thus getting rid of my headspace and leaving room for the container to expand to contain fermentation gasses.

This all seemed quite logical to me. My worry is that I transferred about a week ago and it appears that I am still getting fermentation gas. Not a lot, I can get away with bleeding off the excess about once per day (needed twice per day for first few days). I expected a bit of activity, but figured it would finish in a few days, maybe a week. I haven't checked my SG since I transferred, but I was stable for two days before transferring and at 1.011, which should be about right for a can of extract and 1 kg of adjunct.

I figure one of two things are going on:

One, gas could be the production of slow ongoing fermentation (or other biological processes?).

Two, the vaccum I have created could be slowly equilibrating due to leakage through either seals or permeable plastic (I would think the latter would be very slow).

These seem to be most likely, but I could also have gas coming out of solution, or?

When I crack the cap, I do get a hiss, so I do have positive pressure, which would seem to rule out equilibrium as the sole culprit.

My only concern is that I'm not sure I should bottle if I still have some fermentation activity. It seems like I should get a complete cessation or is this incorrect? If I have a really good seal, then I would be getting a much better indication of activity than you would with an airlock. Is "zero" fementation/yeast activity before bottling a misunderstanding? Do the yeast really stop or just slow way down?

Cheers, Brian

 

[hughman666]

thanks for the info everyone. i racked to the second fermenter this morning and it's just started slowly bubbling away now so im guessing the co2 has taken up the headspace.

best part about this is that i can now put on the next brew in the first fermenter

man it's going to be a great easter....