Wort size in a 5 gallon Corny Keg...

[Kugel]

I've brewed before, many years ago, in plastic buckets - might have been 6.5 gallon buckets for 5 gallons batches.

Just got some refurbished Corny Kegs and want to brew a 5 gallon batch, but don't know if I can safely ferment (primary) a 5 gallon wort in a 5 gallon Corny Keg.

Please advise... and Thanks in advance!

Good Brewing and God bless!

Kugel

 

[VikeMan]

You might be able to do this if you use something like Fermcap-S to prevent krausen.

5 gallons of wort in a "5 gallon" corny leaves a headspace of about 0.3 gallons, which isn't nearly enough for a normal fermentation. Your 6.5 gallon bucket (a typical fermentation bucket size) had 1.5 gallons of headspace. Even that isn't always enough.

 

[Kugel]

Thanks for the reply.

What size batch do folks usually brew/ferment in a Corny Keg?

What size would you recommend to hold the Krausen?

Good Brewing and God bless!

Kugel

 

[VikeMan]

What size batch do folks usually brew/ferment in a Corny Keg?

What size would you recommend to hold the Krausen?

I haven't done a primary fermentation in corny. But here are my old general thumb rules for avoiding blowoff:

1) Adequate headspace in the fermenter. Total fermenter volume >= 1.3 x wort volume.
2) Fermentation temperature control.
3) For high gravity worts (say 1.060-ish or higher assuming #1 and #2 above are covered), use a blowoff hose/reservoir (during the most active fermentation) instead of a regular airlock/spunding valve.

With a corny keg with a volume of approx. 5.3 gallons, rule #1 would work out to about 4.1 gallons of wort. I know there are forum members who are fermenting in corny kegs, so hopefully they'll chime in.

 

[Grizwold1]

I have done 5 brews so far in a corny keg. 4 gallon batches=c. 4.25 gallons into keg, I keep a very slight positive pressure -So far no issues. also allows for an easy cold crash by upping the pressure beforehand and making sure it keeps a positive pressure. I use a 6.5 anvil with a brew bag so the 4 gallons pretty much maxes it out too.

 

[odie]

ball lock cornies hold 5.5 gal.

I ferment a full 5 gallons in cornies all the time. No issues with blow out. I just put a blow off tube on the gas post. usually nothing but co2 comes out.

the exception is hefe...it will blow krausen out, but not the wort.

 

[VikeMan]

ball lock cornies hold 5.5 gal.

@doug293cz measured and found a range of 5.3-5.35 gallons.

 

[odie]

I measured as well.

I got 5.5 gal and can still work the lid without getting it in the wort. 5.5 plus one pint and it's maxed out, wort at the top of lip

 

[doug293cz]

@doug293cz measured and found a range of 5.3-5.35 gallons.

I measured as well.

I got 5.5 gal and can still work the lid without getting it in the wort. 5.5 plus one pint and it's maxed out, wort at the top of lip

Might depend on keg type and manufacturer. I measured a ball lock keg, manufacturer unknown.

I measured the volume by weighing the empty keg, taring out the keg weight, then filling with water up to the point of overflow, and weighing the full keg. I also measured the temp of the water, so that I could use an accurate density to calculate the volume from the weight. The scale I used has a precision of 2 g, which corresponds to +/- 2 ml of volume.

Brew on

 

[odie]

more effort than me...

I just measured out 5 gallons in a graduated fermenter bucket, dumped it in, then added a quart/pint at a time until it maxed out.

either way, I get a full 5 gal batch of wort into my kegs and ferment away without issues.

 

[Hopalong]

I've brewed before, many years ago, in plastic buckets - might have been 6.5 gallon buckets for 5 gallons batches.

Just got some refurbished Corny Kegs and want to brew a 5 gallon batch, but don't know if I can safely ferment (primary) a 5 gallon wort in a 5 gallon Corny Keg.

Please advise... and Thanks in advance!

Good Brewing and God bless!

Kugel

Why sure you can. Besides they do not break, and they can be filled with boiling water to sanitize. Buy the stainless steel connectors if boiling water is used. The nice thing about a corny is that CO2 can be used to transfer the fermented beer into another corny purged with CO2 keep the relief open as it fills. The first pint may have trub in it just dump it.

 

[BongoYodeler]

I have very limited experience with fermenting in a corny keg. My second beer fermenting that way has been in the corny fermenting for 11 days as of right now.

1. Some people ferment, dry hop, and serve all from the same keg.

2. Some ferment and dry hop in the keg, but then move the beer to a serving keg to get it off the yeast, trub, hops, whatever.

3. And some use three kegs. Ferment in keg1, dry hop in keg2, and serve in keg3.

There may even be other combinations or different ways to do this.

Here's what I did.....
My first one, a pale ale, Verdant yeast, OG 1.054. I did option #3. I transferred about 4.0 - 4.5 gallons from my boil kettle. Fermentation and CO2 transfers went fine, no issues other than hop aroma and flavor wasn't as pronounced as I'd hoped. I may have pushed the transfer into the serving keg too fast. I wonder if a slower transfer would have kept the flavor more intact, because the aroma coming off the blowoff during transfer was amazing.

My current beer fermenting is a Raging Irish Red, WLP001, OG 1.058 with no dry hops, option 2 above. I pushed this one a little further by transferring around 4.75 gallons, actually a little more with the yeast starter. I have a jumper running from keg1 gas-in over to keg2 beer-out and on day 2 or 3 I could see krausen moving over to keg2, despite adding 8-10 drops of Fermcap S to keg1 at the start of fermentation. After a day or so it stopped. I'm also using a spunding valve on this one. It's set to 10 psi.

As I said, limited experience. I'm learning as I go.

 

[renstyle]

I was able to run 17-18L (4.5-4.75gal) batches fairly regularly in a regular corny keg.

With a floating dip tube and filter I lose usually one L/qt to trub.

So 16-17L (4.25-4.5gal) without really trying hard.

I'm sure i could squeeze a bit more, but i opted to pick up a 23L (6.1gal) keg as my fermenter instead.