Container sizes for 2.5 gallon batch with dry hop

[jasonmo]

I'm about to try my first 2.5 gallon batch. I am planning on using a 5 gallon carboy for the primary. So there will be a large headspace, which will be filled with C02 during primary fermentation, and that's fine.

I have heard it's not a great idea to rack to a secondary for dry hopping due to the risk of oxygen exposure. So I could dry hop in the primary.

But if I remove the airlock to dry hop, will the C02 rush out and be replaced by oxygen? And if so, will I now be at risk of staling the beer with that large amount of headspace during the dry hop period? Not to mention what if I wanted to take a sample to test FG? Same scenario? C02 rushes out, oxygen comes in, and now I have a very large headspace of oxygen sitting on top of my 2.5 gallons of beer.

I could rack into a secondary 3 gallon container (less headspace) but then I'm risking oxygen exposure during the racking process.

I could primary in a 3 gallon container, but that doesn't leave much room for krausen, does it? All my blowoff hoses are pretty dirty, but I guess I could try that.

So: best ideas for container size / methods for a 2.5 gallon batch with a dry hop?

Thanks everyone!

 

[Oginme]

CO2 is heavier than the mixed gas air we breathe. As long as you don't tip or disturb the air cushion on top of the wort too much, you will be fine. I use the 3 gal better bottles for my 10 liter batches (~2.5 gal) and they work fairly well. Normally, most beers are fine with that headspace, with the exception being higher gravity beers (1.080+). These I either attach a blow-off hose, or more frequently drop the volume down to 9 liters.

 

[jasonmo]

Thanks for that. I'm brewing Yooper's Lakefront-ish clone, it's 1.073. I'll use my 3 gallon carboy for the entire fermentation (won't rack to secondary). I'll be careful when pulling samples and when dry hopping so as to not disturb the air cushion. Then rack to the new kegerator!

Thanks very much Oginme.

 

[RM-MN]

Thanks for that. I'm brewing Yooper's Lakefront-ish clone, it's 1.073. I'll use my 3 gallon carboy for the entire fermentation (won't rack to secondary). I'll be careful when pulling samples and when dry hopping so as to not disturb the air cushion. Then rack to the new kegerator!

Thanks very much Oginme.

With the small opening of a carboy, you'd have to work at it to disturb the CO2 layer enough to get it out that small opening. I open the lid of a 6 1/2 gallon bucket that only contains 2 1/2 gallons of beer and don't worry about the CO2 escaping but I wouldn't do it outside with the wind blowing. :rockin:

 

[AnchorBock]

With the small opening of a carboy, you'd have to work at it to disturb the CO2 layer enough to get it out that small opening. I open the lid of a 6 1/2 gallon bucket that only contains 2 1/2 gallons of beer and don't worry about the CO2 escaping but I wouldn't do it outside with the wind blowing. :rockin:

Agreed. I've done my fair share of 2.5 gallon batches in 5 gallon better bottles and have had no oxidation issues with gravity samples or dry hopping. Just be as careful as you would be with any other fermentation and you'll be fine.


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[jasonmo]

So... I did my first 2.5 gallon all-grain batch and used my 3 gallon better bottle. Brew went great, and I guess the yeast agreed because I went away for a few days and came back to my first ever bung blowout! I think I'll be fine - by the time I cleaned everything up and put the airlock back, it was still bubbling fiercely. I guess I should have used a blowoff hose or a 5 gallon carboy. Still, I loved the all-grain experience and can't wait to taste.