Pressure Fermenting in a Corny

[WeHeavy]

I've read a lot of info about pressure fermenting but I still have a question or two.

For those who pressure ferment in a corny keg how full do you fill your 5 gallon kegs and do you use Fermcap? Also do you start pressure fermentation right after pitching yeast?

I have an old bottle (2Years old) of foam control I've never used, can it go bad with age?

 

[twd000]

rather than testing the limits of minimal headspace, I just brew 8-gallon batches now, and ferment 4 gallons each in two corny kegs, ganged together with some tubing off the gas ports and a tee-fitting

 

[McKnuckle]

Basically ditto here. I ferment 2.5 gallon batches in a 3 gallon keg, then transfer to a 2.5 gallon keg for serving.

Don't make it harder than it has to be. The beer doesn't see oxygen again until you finish drinking it weeks/months later. So you can just ferment a smaller batch size in your 5 gallon corny without worrying about headspace oxidation.

 

[Vale71]

I have an old bottle (2Years old) of foam control I've never used, can it go bad with age?

If it's silicone based then not really. If it's one of the vegetable oil based ones then yes, it will go rancid with time.

 

[Spikybits]

I do 3 gallons in 5 gallon kegs - more so limited by my kettle and grain bills to 3gal. I do not use fermcap and I pressure ferment between 8 and 15psi. Usually the krausen line is between 1"-1.5" thick. I have a pretty good 4 inches or so of headspace in each keg above the high krausen line - more like 3 inches to the gas tube end. I did not cut my gas tubes. The only modification to the keg is to bend the dip tube and fit a braided steel line filter to the end.

I siphon into the fermenting keg and then cap it, and put spunding valve on it. I have 1 or 2 kegs I have to pressure to 3 or 4psi to keep the lid sealed. I let her rip until I feel shes done. Then I crank up the spunding valve to verify theres no active pressure increases from fermentation over a few days. Purge serving keg and close transfer using Liq to Liq jumper. Burst carb at 30psi.

 

[Gnomebrewer]

I mostly do 10.5 gallon batches split into three 5-gallon kegs (3.5gal each) to give two 5-gallon serving kegs. So no fermcap needed.
I rarely start pressure fermenting right away - I normally close off/spund once I'm within about 10 points of FG (either in the ferment keg or transfer then spund).

 

[Horseflesh]

I’ve been using the same bottle of Fermcap since I started brewing ~8 years ago and it still seems to be fine.

 

[BeerFst]

4.5 gallons in 5g corny. I use fermcap but use a blowoff for peak ferm, the. Cap with the sound to carb at the end. so not true pressure fermenting. That said I’ve only had one beer get yeast in the blowoff so I’d be totally comfortable with putting a sound on early

 

[BruceH]

I fill the keg to about 1" below the gas tube but I only finish in the keg. Most of my fermentation takes place in a fermentor.

 

[greywolf]

I stopped using fermi cap when I ran out. Don’t see any difference. Trimming the length of the gas in tube helps. Fill to about and inch or so below the gas tube. I have two fermenting right now. One has a blowoff and the other is spunding set at 10 psi. No difference in blowoff. Floating dip tubes. Ferment and serve same keg.

 

[greywolf]

I will say that the blowoff keg finished fermentation several days sooner. Tasted the same. Just quicker. For the next batch I pulled the keg lid 'o' rings and snapped the lids on. Will vent out the seam . Plan to reinstall them when fermentation is close to the end and then let them build pressure. We'll see in 5 days.

 

[Bigdaddyale]

https://github.com/vitotai/BrewPiLess/issues/218