5 gallon Cornelius keg filled to 4 and 5 gals

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Cider Wraith

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...responses to my post of a carboy at different fill levels got me reading carboy horror stories (ouch) so I'm beginning experimenting with fermenting in a Pepsi keg. For my first run I've just replaced the dip tube with a spare gas tube and I'll just do a ball connect to hose into a bottle of StarSan. (I understand I can get fancier but I'm just going to give it an initial go with two gas tubes at about 3.75 gals and I'll do a conventional auto-siphon ... later I can trim down a dip tube to get a pressurized transfer and maybe drill the lid for a stopper/air lock or whatever to get a little fancier)

...anyway, I read at what I would have guessed would have been a reliable site that "...Cornelius Kegs are listed as 5 gallon kegs but will actually hold closer to 6 gallons by volume" which didn't seem to jive with what I've experienced so I thought I'd check it out. Well, hm, doesn't look like it to me ... at least not one of my Pepsi kegs. What about yours?

Four gallons:
pepsi_1.jpeg

pepsi_2.jpeg


Five gallons ... here touching the top of the water which is maybe a half an inch above the bottom of the gas tube:
pepsi_3.jpeg

pepsi_4.jpeg
 
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We have done fermentation in a keg, We did not remove any of the dip tubes and just put on a gas connector with a tube into a gal milk jug filled with water. We would transfer the beer to another keg after getting rid of any trub (first out of the tube) when done. If the trub blocked the exit, we just added CO2 to the outlet and let it resettle. We finally bought Conicals so we have not done it in a while.

We left about 2 " below the gas dip tube.View attachment 778436
 
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Funny that you mention that, because just this second I was doing a search for floating dip tubes. I was just running through my mind the different scenarios for transferring from a ferment corny to a serving corny, and I got to thinking that maybe trimming off the bottom of the dip tube would be the right way to go, but I just now was looking up floating end dip tubes. I'm feeling like I'm onto something with fermenting in corny's so now I'm going to begin researching that process in earnest. And yeah ferment and serve from the same keg. I've got a lot of reading to do on this new path - Thanks for the comment
 
I saw some people cut the dip tubes, but the clearest beer is always at the top anyways. I use floating dip tubes in the kegs either way.

I even fermented and served a fruited sour from the same keg and it was banging. Didn’t last very long.

If you want to transfer to another keg it’s very easy. Ton of videos on YouTube. No oxygen is a huge plus. Spunding valve come in very handy.

 
Yeah, I've been a carboy fermenter and had great success but now I'm spooked of them. So now my eyes are opening to the possibilities of fermenting in cornys and obviously it's a well developed art but I'm just now waking up to it. My latest thought was that if using different fermenting and serving kegs, then when the serving keg is empty and blowing C02, well, you've paid to fill it with C02 and the alcoholic beverage that just came out of it was perfectly clean so ..... so without opening it just immediately fill it right back up again with the next batch of the identical stuff. Even crosses my mind to fill it from the gas port so there would be extra splashing and carbonation. I'm guessing folks would cringe at the thought but why not. Then you would get an absolutely non-air transfer. Of course you couldn't do that indefinitely but maybe a few times. Oh well, I know you guys have this all throughly figured out so my job is to begin doing my research
 
Ok, for anybody that's reading I've got one for you. Have you ever seen a food-grade plastic see-through cornelius keg fermenting-only top? I've searched for them and come up with nothing. But think about it, what if you could have the advantage of stainless steel corny fermenting and add the ability to check the fermentation with a plastic window that would actually never touch the liquid. Does that exist? I would have to think that would sell well if it was offered.
 
Ok, for anybody that's reading I've got one for you. Have you ever seen a food-grade plastic see-through cornelius keg fermenting-only top? I've searched for them and come up with nothing. But think about it, what if you could have the advantage of stainless steel corny fermenting and add the ability to check the fermentation with a plastic window that would actually never touch the liquid. Does that exist? I would have to think that would sell well if it was offered.

No, never seen that. I'm not sure exactly what problem it solves. You can take off a corny lid and look at fermentation and take gravity readings that way. Taking off the lid for a moment isn't a big deal.
 
I been fermenting solely in a spare pin lock keg for the last year or so and feel that it has drastically improved my beers. I brew 4.5gal batches to leave some headspace during fermentation. Your setup is exactly how I do it - blowoff tube attached to the gas post with the end placed into a jug of starsan/water mix and floating dip tube for transferring to serving keg.

If watching fermentation or having concerns about pulling samples to test gravity, there are several ways around that. I use a tilt hydrometer that allows me to track fermentation and temperature, so I have no concerns of needing to look at my beer to see active fermentation. If you don’t have a tilt and want to draw samples, simply use a picnic tap and charge your keg with ~2psi of CO2 to draw a sample.

The biggest benefits I have found with keg fermenting is closed transfer, which has eliminated all oxidation issues I previously experienced, and fermenting under pressure if desired. This may seem daunting at first but is actually very easy - several videos on YouTube.
B7AAF48A-386E-401D-ABDA-D022827D235A.jpeg
 
corny kegs hold 5.5 gal. You can ferment a full 5 gallons in one and not have blow out issues.
 
well Kveik is rather....explosive...

Hefe yeasts will blow out too. Even under pressure.

But any other ales have never blown out on me. And lagers are even less active.
 
I should go measure my legs now but OPs kegs seem like they must be small? I'm 99 percent my ball lock cornies hold about 5.5 gal to the brim
 
I've bought used pinlock, ball lock, new ball lock, and so forth.
I have owned 17 different kegs, and there's really not a single match between any of them.
That said, I'll bet all the pinlocks hold generally within a few % of the same total volume, and the same for all the ball locks (not counting the 3 new 2.5 gal ball locks).
 
I should go measure my legs now but OPs kegs seem like they must be small? I'm 99 percent my ball lock cornies hold about 5.5 gal to the brim
ball lock hold 5.5gal total usable. that means enough head space to insert the lid and close it without getting it in the beer.

5.5gal plus one pint is to the absolute rim but then you are going to be making a mess working the lid.

5.0 is up to the top weld line on most cornies. The domed top is about 2 quarts more. That is your typical recipe volume and the 2 quarts head space seems to work well for any krausen...EXCEPT the dreaded hefe...that is coming out no matter what so have a good container for the blow off tube.

I did several fill tests and that's pretty consistent volume across all my ball locks regardless of manufacture.
 
ball lock hold 5.5gal total usable. that means enough head space to insert the lid and close it without getting it in the beer.

5.5gal plus one pint is to the absolute rim but then you are going to be making a mess working the lid.

5.0 is up to the top weld line on most cornies. The domed top is about 2 quarts more. That is your typical recipe volume and the 2 quarts head space seems to work well for any krausen...EXCEPT the dreaded hefe...that is coming out no matter what so have a good container for the blow off tube.

I did several fill tests and that's pretty consistent volume across all my ball locks regardless of manufacture.
...well you're making me a believer ...maybe I goofed up the test ... I'll try it again sometime ... my preferred batch sizes are usually going to be 3.5 ~ 3.7 gals and in addition to avoiding blow out gives me something easier to lift and tote around - thanks for the replies!
 
I begin my fermentation in a bucket and then transfer to a keg with a floating dip tube typically around 1.030 or so (roughly after 48 hours), trying to get beyond peak krausen and with still enough CO2 being produced to mitigate oxidation potential. I also will be reducing volume by leaving maybe a quart of so of trub which also helps. I typically add a spunding valve at that point and set it at 12 psi, mainly to use some of the naturally produced CO2 and to have the beer reasonably carbonated by the time I do close transfer to serving keg. I use Kveik nearly exclusively and had real blowoff issues. With this process I think I am getting pretty close to 5 gallons in the final serving keg.
 
Ok, for anybody that's reading I've got one for you. Have you ever seen a food-grade plastic see-through cornelius keg fermenting-only top? I've searched for them and come up with nothing. But think about it, what if you could have the advantage of stainless steel corny fermenting and add the ability to check the fermentation with a plastic window that would actually never touch the liquid. Does that exist? I would have to think that would sell well if it was offered.
https://www.anvilbrewing.com/5-gallon-fermenter-king-junior
Almost bought this today.
 
When I picked up my Fermzilla, it came with a length of silicon tubing and a floating tube, you can purchase them on Amazon for about $20, and I've been using them in kegs without an issue. They come with a short tube to replace the liquid tube in the keg.

https://www.amazon.com/Stainless-Fe...ps,119&sr=8-1-spons&psc=1&smid=A1VGCA0AS7QDJG
I bought one of these for my fermentation keg set up. The other floating dip tube I had always had a problem of not staying under the liquid line. This one is perfect. The filter not only filters out hops/trub, but also helps weigh the tube down. Love it.
 
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Fixed that for you.
I have had krausen out the gas tube with 4.5 gal wheat beer in corny keg; with 4.75 gal Voss Kveik, and with 4.75 gal WY1007 4th generation overbuild.

Add most Belgian yeasts to that list, too. I've had 7.9 gallon buckets with 5 gallon batches with Belgian yeast push krausen into the airlock. I routinely get blowoff tubes filled with krausen on one gallon batches in 4 liter jugs because 10% headspace often isn't enough with a lot of strains.

Whirlfloc avoids these issues though. Pretty much any time I have a thought of concern about a clogged airlock or blowoff tube I add whirlfloc when I pitch. Never had problems with foam stability.
 
this solved all my floating dip tube problems. A 1/2" SS nut that slides up and down the silicone hose. It keeps the hose always in a dip and thus keeps the pick up always below the liquid line
Nice
 
...EXCEPT the dreaded hefe...that is coming out no matter what so have a good container for the blow off tube.
By chance, have you ever tried adding a defoamer when fermenting? I used to use a few drops of olive oil (which is also great for yeast starters in tiny amounts, even just before wort boils). Now, I use Birko Patco 376 which is pure vegetable oil (no silicone!) which you can get by the gallon or AIH used to sell it in little 2oz(ish) bottles for $5. With Patco, even a 3x yeast starter (1L -> 2L -> 3L) in a wee heavy scottish ale only produces 1/2" of krausen. I not a hefe fan, but curious if Patco works just as efficiently for hefes, too.
 
I try not to add anything that is not part of the recipe.
 
I have measured the volume capacity of my ball lock kegs (by weighing the water - more accurate than measuring cups) at 5.3 - 5.35 gal. Just another data point.

Brew on :mug:
 
liquid volume expands and contracts based on temperature.

Had a fuel truck fill us to capacity on the ramp in Vegas at night. A couple days later we return to find a bucket under the fuel vent with some of our jet fuel in it...the things you learn as a student...
 
liquid volume expands and contracts based on temperature.

Had a fuel truck fill us to capacity on the ramp in Vegas at night. A couple days later we return to find a bucket under the fuel vent with some of our jet fuel in it...the things you learn as a student...
:off:When I was fly Gulfstreams, originally the specs called for a maximum fuel weight versus gallons. You could "overload" the fuel on a cold day. They eventually changed to Maximum gallons. All planes have a fuel vent system that will leak fuel on a ramp if left full most of the time.
 
liquid volume expands and contracts based on temperature.

...
Yup. I compensated the weight to volume calculations for water temp (divided the weight of water in the keg by the density of water at its current temp) when I determined the keg volume.

Brew on :mug:
 
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