question about primary

[guscampag]

I am pretty new to beer brewing. I started batch yesterday. Extract. Yooper's English Brown Ale. I made it a couple of times and it came out good. Well, I made a double batch (10 gallons). I have it in a 22 gallon Brute container EDPM. Do I need to get it into airtight containers or does it matter. I know with wine the air is good for it in primary, but I don't know if that is true for beer or not?
Thanks for advice.

 

[C-Rider]

That's 12 gallons of head space. Might be to much. The yeast will creat CO2 which is heaver than air and will try to fill the head space, some will leak out. Air tight would be better I think but not that cridtical. But then I only do 2 gallon batches.

 

[daksin]

If you can get on it, you should be ok. CO2 will fill the headspace, and as long as you don't take the lid off until you're ready to bottle/keg, you'll be fine. Is the container really EPDM, or is it HDPE?

 

[MagicMatt]

The yeast will creat CO2 which is heaver than air and will try to fill the head space

Let's not start that whole "CO2 blanket" myth again. Gases diffuse.

 

[fuelish]

Let's not start that whole "CO2 blanket" myth again. Gases diffuse.

Unless they've filled the entire space, but, well.....12 gallons is a LOT of space....heh

 

[MagicMatt]

Unless they've filled the entire space, but, well.....12 gallons is a LOT of space....heh

I'm not sure I follow. Gases always fill "the entire space". Unless someone is creating a vacuum in their fermenter...but that's not what we're talking about here.

Carbon dioxide is not heavier than oxygen or water vapor, but it is denser than those gases. Thus, CO2 will, on average, equilibriate slightly lower than O2 in a gravitational field. But the difference in the force of gravity is very small compared to the random thermal motion of the molecules, thus the effect is effectively negligible in day to day life. Consider this:

You have an empty keg that you just sealed. The entire volume of the keg is filled with gas (atmospheric levels). Now if you pump in CO2 to say 15psi, the CO2 will mix with the gases inside. The gases are evenly mixed and as the pressure inside the keg is raised, it will become higher in CO2 concentration than other gases. If you then disconnected the CO2 and left the keg sitting for a week, you wouldn't find that the CO2 has "settled" out or anything of the sort. There will be next to no stratification of the diffused gases.

Case in point: http://www.jbc.org/content/73/2/379.full.pdf

 

[rlmiller10]

If CO2 really stratified out, on a still night every valley or bowl such as where Laramie WY sits would fill with CO2 and kill all the inhabitants.

 

[joshesmusica]

yeah you don't want too much headspace. my method is go with as little as possible without needing a blow-off tube for the normal yeasts at low temps. but if i know a yeast will need a blow-off, i use it anyways.

 

[fuelish]

Perhaps I misspoke....I guess meant that, if you have a full carboy, a blowoff system of some sort with a good seal , a vigorous ferment (as most beers seem to do), that small space will be filled with enough CO2 that O2 would likely be a non factor, especially for the short length of time most beers stay in the fermentor....not like we're talking bulk aging mead or wine, here.....folks seem absolutely terrified of oxidation and infections.....it's not hard to prevent either. BUT, 12 gallons of headspace is excessive, no matter how ya look at it