Keg fermentation headspace

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

Djangotet

Well-Known Member
Joined
Nov 15, 2022
Messages
82
Reaction score
12
Location
California
Hello, I plan to ferment in a 2.6 gallon keg. I want to link it with an empty keg that has a spunding valve to keep about 10psi of pressure. Am I able to ferment a full 2.5 gallon batch or should I dial back to 2 gallons? Thanks?
 

day_trippr

Structural Duct Tape Applications Engineer
Joined
May 31, 2011
Messages
39,256
Reaction score
22,546
Location
Stow, MA
I'd definitely "dial back" from 2.5 gallons, the question is how much.
If the OG of this brew is modest (say 50 points or less), the temperature is controlled, and the strain used isn't known for histrionics (eg: S04 if allowed to warm) 2 gallons might work ok...

Cheers!
 
OP
OP
Djangotet

Djangotet

Well-Known Member
Joined
Nov 15, 2022
Messages
82
Reaction score
12
Location
California
I'd definitely "dial back" from 2.5 gallons, the question is how much.
If the OG of this brew is modest (say 50 points or less), the temperature is controlled, and the strain used isn't known for histrionics (eg: S04 if allowed to warm) 2 gallons might work ok...

Cheers!
Sounds good, thank you
 

A.Homebrewer

New Member
Joined
Mar 26, 2022
Messages
4
Reaction score
3
Location
Northern Iowa
I fermented 70 2.5 gallon batches in 5 gallon kegs and had kruesen in the airlock several times. Seems to me this was the right amount of head space. Kept the keg in my fermentirator (temperature controlled refrigerator) and used a PicoBrew Z and with a shortened dip tube. I wised CO2 to force it out into bottles.
 

TBA

Well-Known Member
Joined
Sep 24, 2020
Messages
115
Reaction score
42
I ferment 4 gallons in a keg all the time. When using a yeast that makes a really big Krausen (like Verdant) I back off to 3.5 gallons. I purge the dry hop and serving keg at the same time, running tubing between them and then into a jar of StarSan. I haven’t tried spunding yet.
 

khannon

Guy who really knows where his towel is.
HBT Supporter
Joined
Feb 21, 2016
Messages
587
Reaction score
499
Location
Amherst
I do not have much experience, but there is a product called fermcap that might help with fermenting with tighter headspace.
 

odie

Well-Known Member
Joined
Dec 18, 2016
Messages
2,105
Reaction score
1,205
Location
CC, TX
I've been fermenting 5 gal in a 5 gal keg with no issues so far. there is about 0.5 gal headspace in a corny. a 5 gal corny hold 5.5...so I assume your 2.6 corny holds 3.1 total volume.

I've not had any issues fermenting full "rated" volume. Well the exception being a hefe. But even that did nothing other than blow krausen out the blow off tube, not any beer loss.
 
Top