Setting up Corny as fermenter?

moxie · 10-14-2010, 02:51 AM

I have browsed through a few threads discussing this option, but I have some questions that are still un-answered...

I am trying to retire the plastic fermentation vessels... I would like to ferment in stainless steel, and I would love to buy a conical, but it just is not in the budget at the moment. Fermenting in a corny keg seems like a decent option but here are my questions:

How much volume can you get out of a corny primary?
What is the best way for setting up the corny for fermentation? Did you somehow rig it for an airlock? I have seen some corny lids drilled out for a bung/airlock, is this possible to DIY this, or is there a better/easier way to set up a blow off tube?
What are the pros/cons of fermenting in a corny compared to a plastic vessel?

Any general tips on setting up a corny as a fermenter?

Cheers

Scut_Monkey · 10-14-2010, 04:00 AM

I occasionally will ferment in a corny. I typically split a 5 gallon batch between two cornies. I really only do this when one of my 15.5gallon sanke kegs are full or dirty. I would say comfortably you could ferment an average of 4.25 gallons in each keg and possibly more if you use something like Fermcap-S.
I have found that simply locking the the pressure relief valve open with the pull ring turned works well as an airlock. This would be inside my fermentation fridge away from fruit flies. Other than this taking a "domed" pressure relief assembly out and putting in a rubber stopper and airlock works well. Or third, you can take the gas post off and the gas diptube out and insert a piece of tubing on the threaded portion with an airlock coming out of the tubing.

Pros for using a corny to ferment: (off the top of my head)
1. Easy to transfer with no O2 exposure by pushing with CO2
2. Relatively easy to clean corny SS
3. No chance of scratching SS like with plastic
Cons
1. Must sanitize more parts including poppets etc
2. Hard to ferment a full 5.5-6 gallon batch

smellysell · 10-14-2010, 04:04 AM

I ferment exclusively in cornies these days, and typically finish with really close to 5 gallons (I fill to the brim and use ferm-cap). I just unscrew the gas post and put a piece of tubing over the threads and into a blowoff container.

lanvp · 10-14-2010, 04:12 AM

I use corny kegs as secondary fermenters. My brew batch size is ~5gal. So in my case is not a good option for a primary fermenter. Now, as secondary is a great option.

I believe the corny keg has a capacity of 5gal (18.9L).

Anyway, here is a site that sales a modified corny lid (just as an example).

http://www.homebrewing.org/Cornelious-Keg-Lid-for-Secondary-Fermenter_p_999.html

Hope this helps.

Cheers!

Scut_Monkey · 10-14-2010, 04:56 AM

They do work excellent as secondary fermenters. I love them for this. I can really reduce the chance of oxidation by racking with CO2 and purging the headspace with CO2. That eases my mind quite a bit.

lanvp · 10-14-2010, 06:23 AM

Quote:

Originally Posted by Scut_Monkey

They do work excellent as secondary fermenters. I love them for this. I can really reduce the chance of oxidation by racking with CO2 and purging the headspace with CO2. That eases my mind quite a bit.

I second that! It is one of the reasons why I really like them as secondary fermenters.

Cheers!

smellysell · 10-14-2010, 04:53 PM

Quote:

Originally Posted by lanvp

I use corny kegs as secondary fermenters. My brew batch size is ~5gal. So in my case is not a good option for a primary fermenter. Now, as secondary is a great option.

I believe the corny keg has a capacity of 5gal (18.9L).

Anyway, here is a site that sales a modified corny lid (just as an example).

http://www.homebrewing.org/Cornelious-Keg-Lid-for-Secondary-Fermenter_p_999.html

Hope this helps.

Cheers!

I've never checked the exact capacity, but it's closer to 5.5 gallons. That being said, even with Ferm-cap I usually have a lot of blowoff.

moxie · 10-14-2010, 04:58 PM

I am intending to use them for a primary... In my current set-up, I have basically been using a corny as a secondary, racking to kegs directly from my primary, throwing it in the fridge for a couple of weeks, then hooking it up to the lines. Are there any tips out there in terms of using a corny as a primary in particular? I am interested in the foam control additive... I figured I would require a lot of head space in the corny for fermentation since it is a very narrow vessel, I was worried about losing a lot of volume. I wouldn't mind ending up with 2 3/4 full kegs as long as I can match it to a single brew batch.

lanvp · 10-15-2010, 06:10 AM

Quote:

Originally Posted by smellysell

I've never checked the exact capacity, but it's closer to 5.5 gallons. That being said, even with Ferm-cap I usually have a lot of blowoff.

I stand corrected...

Cheers!

GillandCo · 10-15-2010, 07:44 AM

Quote:

Originally Posted by Scut_Monkey

They do work excellent as secondary fermenters. I love them for this. I can really reduce the chance of oxidation by racking with CO2 and purging the headspace with CO2. That eases my mind quite a bit.

I never even thought of this...I have been transferring to secondary when i could be going straight to the keg. Will I suck up and yeast left over on the bottom after the first couple pints? If so do you guys let the beer sit in the cornys at room temp, then poor off a pint or so before you force carb. Or force carb and let it settle in the fridge then start pouring!