Primary fermentation in corny keg

old and dead thread but i need to subscribe for the info.

Hey everyone! This is my first post. I decided to join as i have been reading this forum for a while. I hope to turn this post into an all-revealing article on keg fermenting.
I recently obtained three free corny kegs from the brewer at my work. With a little maintenance and a new lid or two, these kegs ended up really improving my setup. Two of them are taller and thinner than the rest so they will not fit in my mini-fridge keggerator. They both still say 5 gal on the side. I think they are spartan style. This height makes them of less use for traditional kegging duties so I thought their only use to be for storing grains and/or hops sans oxygen.
Then I was looking at SS conical fermenters and also at their large prices. Somewhere I got the idea to look at using kegs for fermenters online. I thought it was brilliant. These kegs have a roughly conical shape at the bottom, minimizing surface area of beer/cake exposure. They don't have a bottom valve, but they do have the next best thing, a beverage tube! One of mine in particular goes all the way to the bottom an is bent to fit into the round divot in the bottom. Perfect for using pressure to push as much of the yeast cake as possible out through a cobra tap or similar.
I have no desire to ferment under pressure and also I have never used the tube/bucket method for air locks. My first batch in a keg was a secondary ferment. At first I tried just using an S airlock and a stopper with a hole on the gas in connector (threaded quick disconnect kind). It didn't work very well for two reasons, over time the angle of the airlock would sag threatening to fall off the connector. Also I thought I had a stuck ferment on my first primary batch using this method. It turned out that with all the poppets and springs and such somehow the co2 wasn't being allowed free passage. It was just building up in there.

So the next mod to the airlock setup was to block the metal tube connector off entirely and just shove a hole stopper into the top of the disconnect and shove the airlock into that. Of course the only way to make that work is to remove all the springs/poppets from under the post and also the disconnect so there's a straight shot from the tank to the airlock. Add a tubing clamp to the angled part and you have a great working airlock.

One of the main problems with keg fermenting is that if you are the kind that likes to throw the hydrometer in the batch it's more difficult to read. I recommend having a flashlight handy because it's dark in there. Also you have to feel around the top of the inside of the keg to make sure you get it clean.
Here's my method:
Rack from cooled pot into sanitized keg.
Top off with cool water.
Take a hydrometer reading.
Pitch yeast.
Attach airlock to poppetless post.
Primary ferment.
Being sure not to shake, attach co2 to re-poppeted gas post.
Attach cobra head with short amount of tubing to beverage post.
Remove yeast (NOTE: This does not remove all the yeast as he sides are not steep enough). extra : to remove more yeast give the keg a small shake after most of the yeast cake has been pushed out, then let sit for at least 20 mins and push more out.
Remove poppets, relieve pressure, and reattach airlock.
Continue to secondary ferment.
At this point I like to transfer into a shorter keg so that it'll fit into my fridge and also because I don't want the gunk on the sides of my serving keg (probably won't make a difference though, you could use the same keg). To do this you need two beverage connectors on the same tube. Connect the gas to the dirty fermenter keg (the full one), remove yeast once more and then connect the two beverage posts together. It's nice to have an unused gas post to pop on the receiving keg so you don't have to hold the pressure valve open. Also it's nice to purge the oxygen out of the receiving keg first. Turn on the gas and watch as the beer flows up one beverage tube and down another into an oxygen-less environment. When you hear sputtering you're done. Then cool, carbonate and serve, be sure to brag to friends about how this beer never touched oxygen after the pitch.

I've done a few batches this way, and so far I have never had a problem with head space. Then again I always use dry yeast that I sprinkle on top. Personally right now I don't know if I'll use carboys anymore unless there's some reason like I want to see what's going on or whatever. This system is a work in progress. One thing for those of you who use pure oxygen or even air to oxygenate your wort: in theory it should be really easy to connect oxygen to the bev/out port on your keg and just bubble through the liquid just like co2, then shake under pressure for added absorption. I welcome any comments, questions, suggestions, this forum has to offer. I hope that I have encouraged some of you thinking about using kegs as fermenters to give it a try. You can use a keg/lid that does not hold pressure at all. It just has to keep dust out. I think there are many advantages to doing things this way and perhaps with a little refinement and some group support this could be the standard for anyone with a keg setup.

For anyone who may be controlling temperature and want space measurements with my airlock installed, they are 27 1/2" tall and 9" diameter for the low profile kegs and 30" tall and 8 1/2" diameter for the firestone or spartan taller kegs.

From your pictures I see you have lids with a removable PRV. No need to put the disconnect on for the airlock, just use a wrench to remove the PRV and then all you need is a drilled #2 stopper for the airlock and away you go.

I have more lids than kegs, so 3 lids always have the PRV removed and I use them exclusively for fermentation.

dcbw said:

From your pictures I see you have lids with a removable PRV. No need to put the disconnect on for the airlock, just use a wrench to remove the PRV and then all you need is a drilled #2 stopper for the airlock and away you go.

I have more lids than kegs, so 3 lids always have the PRV removed and I use them exclusively for fermentation.

Click to expand...

That does sound easier but then you have to take the whole lid off to push the yeast cake out. With the way i do things you just replace the spring parts of the keg post/disconnect and use as normal. These are just preferences.

For the folks looking for spunding valve parts. I just built one for naturally carbing one or two corny kegs at the same time. I guess it translates into a secondary fermentation/conditioning. Check out the thread for the parts - https://www.homebrewtalk.com/f35/spunding-valve-build-help-505289/
All from Amazon.

I primary in 5 gal cornies almost exclusively now. I do 2.5-3 gallon batches, which fits easily. If you want to do 5 gallon batches, just brew and ferment the 5 gal recipe at only 4 gallons, then top off with a gallon of water in the serving keg when ferm is done (10-15 gal cornies are too expensive).

My process:

• Dump hot from BK right to keg,
• Seal up the keg and put the keg in the pool in summertime or in a water filled bin outside in the winter time. It'll be chilled in an hour with no effort on my part.
• Check temp before pitching yeast. Reseal and leave relief valve open to vent. Cover top of keg with grocery bag.
• After 3 days I attach this pressure gauge and valve to the gas port and let the beer finish fermenting and carb to 5 psi at the same time...http://www.williamsbrewing.com/0-60-ADJUSTABLE-PRESSURE-RELIEF-VALVE-P3453.aspx
• When it comes time to transfer, the beer is already pressurized enough to transfer to another keg. I don't do the post to post closed system transfer. I use a cobra tap with a racking cane jammed in it that's long enough to send the beer straight to the bottom of the new keg through the open lid. purge the new keg with co2 first

.

That's basically it.

Weezy said:

I primary in 5 gal cornies almost exclusively now. I do 2.5-3 gallon batches, which fits easily. If you want to do 5 gallon batches, just brew and ferment the 5 gal recipe at only 4 gallons, then top off with a gallon of water in the serving keg when ferm is done (10-15 gal cornies are too expensive).

My process:

• Dump hot from BK right to keg,
• Seal up the keg and put the keg in the pool in summertime or in a water filled bin outside in the winter time. It'll be chilled in an hour with no effort on my part.
• Check temp before pitching yeast. Reseal and leave relief valve open to vent. Cover top of keg with grocery bag.
• After 3 days I attach this pressure gauge and valve to the gas port and let the beer finish fermenting and carb to 5 psi at the same time...http://www.williamsbrewing.com/0-60-ADJUSTABLE-PRESSURE-RELIEF-VALVE-P3453.aspx
• When it comes time to transfer, the beer is already pressurized enough to transfer to another keg. I don't do the post to post closed system transfer. I use a cobra tap with a racking cane jammed in it that's long enough to send the beer straight to the bottom of the new keg through the open lid. purge the new keg with co2 first

.

That's basically it.

Click to expand...

I think next batch I'm going to do this. All my beers come out with this sour taste at the end and I've been slowly switching processes and equipment to find my error. Now I'm thinking racking cane might be the problem, or my house just has sour yeast floating around. For pouring I'm thinking about using this wide mouth plastic canning funnel i got at walmart. I think I'll still use my fancy keg airlocks though. I'll break out my laser thermometer too.

Personally, I have fermented in kegs twice. Both times were a 2.5 gallon batch of a clone of pyramid's Hefeweizen in a 3 gallon keg. They were also kept under a constant 15psi using a spunding valve that I built myself.

My results? Well, the beer was pretty good. Good, not great. But I think that was due to the recipe. Also, I only own one 3 gallon keg. This meant that I had to use the same keg for both primary and serving. Not exactly favorable cause of the trub mess.

My suggestions if you're going to go this route, pressurized fermentation or not, use fermcap. The stuff really works. Number two, if you're a cold-crasher, let your keg pressurize over your target serving pressure first. I found that a spunding valve set to 15psi dropped to 7psi after cold crash. If you're keg-fermenting to try to carbonate as well, either remove the airlock or spunding valve a day before crashing. Finally, use a spare keg for serving. Transfer the beer under pressure first to leave the crap behind


Sent from my iPhone using Home Brew

Weezy said:

I primary in 5 gal cornies almost exclusively now. I do 2.5-3 gallon batches, which fits easily. If you want to do 5 gallon batches, just brew and ferment the 5 gal recipe at only 4 gallons, then top off with a gallon of water in the serving keg when ferm is done (10-15 gal cornies are too expensive).

My process:

• Dump hot from BK right to keg,
• Seal up the keg and put the keg in the pool in summertime or in a water filled bin outside in the winter time. It'll be chilled in an hour with no effort on my part.
• Check temp before pitching yeast. Reseal and leave relief valve open to vent. Cover top of keg with grocery bag.
• After 3 days I attach this pressure gauge and valve to the gas port and let the beer finish fermenting and carb to 5 psi at the same time...http://www.williamsbrewing.com/0-60-ADJUSTABLE-PRESSURE-RELIEF-VALVE-P3453.aspx
• When it comes time to transfer, the beer is already pressurized enough to transfer to another keg. I don't do the post to post closed system transfer. I use a cobra tap with a racking cane jammed in it that's long enough to send the beer straight to the bottom of the new keg through the open lid. purge the new keg with co2 first

.

That's basically it.

Click to expand...

You can ferment in two kegs and combine in the serving keg. This is what I do for 6-7 gallon batches. Then you can bottle right out of the fermenter with what's left over by using a picnic tap/bottle wand and a little honey in each bottle. Works like a charm.
Your method seems pretty awesome. I don't understand why you don't do the jumper transfer though, it's so easy and closed. Do you keg your half batches in 5 gallon kegs or do you have 2.5 or 3 gallon kegs? I wish I had some 2.5 gallon kegs so I could do some smaller batches. I used to do 4 gallon batches (which means 3.5 in serving keg) and it's hard to get a seal on the keg lid in the serving keg sometimes with all that headspace. I guess keg lube helps. Plus it's a lot of extra headspace, I'm always wondering if I'm adequately purging all the O2 or not. Plus, I can't stand not having a full keg! I know, that's psychological...

The two kegs is a nice idea.

I serve in both 2.5 & 5 gallon kegs.

My fermentation keg doesn't have a cut dip tube, so using a cobra tap and racking cane lets me pour off trub first then move it to the keg when its running clear, and I know when the krausen is coming long before it gets into the serving keg...and I didn't have to buy any parts. It works fine and I don't have to ruin a dip tube.

Not completely a closed transfer? True but I'm not worried about 2 minutes exposure to air through the keg lid. Its still being transferred under a blanket of co2, so risk of oxidation is no different either method.

Ok, i thought I would make another post to report my findings. Since my last post i have also purchased 10 x 5 gal spartan or firestone kegs from my local pepsi bottling pant. They are all $25 a piece but I will end up putting new orings and also universal poppets all around so that's a minimum of $7 in additional costs but I can live with that. I wish they were low profile ones though, as I can only use these ones for storage of beer/grains/hops or for fermenting. Still I have 15 now which pleases me greatly. I kind of feel like become a keg hoarder because my stash makes me so happy. I bought huge bags of orings from mcmaster as guided by this post. My first batch went smoothly. I didn't wait any time to pour into my sanitized fermenter keg which luckily the bottom has always been detached from, more surface area. I threw it in a 20 gal tub I had sitting in the below freezing weather outside. I did deception cream stout. When I went to push the yeast cake and cold break from my fermenter a week after brewing I ran into a flow problem. I simply removed the beverage tube and cleaned and sanitized before putting it back in. Still very little came out so I had to pull the springs and poppets out of both the beverage post and also the quick disconnect. Also it works better if you don't use a picnic tap because it will get clogged. Just be careful and use the gas disconnect to kind of control what's going on. I think I might have to cool in the pot just long enough to get the cold break to settle then pour into the sanitized keg to cool further. If any of you paying attention to this thread have a suggestion as to how cold and/or how much time is needed to get most of the gunk to settle after boil I would appreciate a little guidance. These are all just minor problems I'm working out. I'm still really liking fermenting in corny kegs. Anyways CHEERS!

Are you trying to harvest yeast through the dip tube? that's difficult as the dip tube is only going to remove a small amount of trub/yeast that is right around the end of the tube. The rest of the trub/yeast isn't going to flow to the end of the tube.

I've never had a cobra tap clog. I imagine adding some additional co2 pressure would free it up.

Don't dump the hot break and hop gunk from the kettle into the keg.

Weezy said:

Are you trying to harvest yeast through the dip tube? that's difficult as the dip tube is only going to remove a small amount of trub/yeast that is right around the end of the tube. The rest of the trub/yeast isn't going to flow to the end of the tube.

Click to expand...

I only use cornies that have a round bottom and a curved beverage tube, namely firestone/spartan. I then loosen the yeast by picking up and kind of swinging it pendulum style a little and then waiting for it to settle a little. This seems to be the best I can do. It can be done over a few days. Using firestone kegs is better becauseif you end up with 4.5 gal there's an extra inch of headspace but they also have a different height/width ratio if you pay any attention to the "shorter is better" thinking expressed in the other "fermenting in keg" thread.

Weezy said:

The two kegs is a nice idea.

I serve in both 2.5 & 5 gallon kegs.

My fermentation keg doesn't have a cut dip tube, so using a cobra tap and racking cane lets me pour off trub first then move it to the keg when its running clear, and I know when the krausen is coming long before it gets into the serving keg...and I didn't have to buy any parts. It works fine and I don't have to ruin a dip tube.

Not completely a closed transfer? True but I'm not worried about 2 minutes exposure to air through the keg lid. Its still being transferred under a blanket of co2, so risk of oxidation is no different either method.

Click to expand...

I thought I'd mentioned it, but I bent my dip tubes up so there's about 1/3 gallon deadspace. I cut a couple a few years ago and wish I hadn't.
I don't pick up any trub and don't have to worry about hop sludge clogging up the system. It does leave juuust a little more beer behind than I'd like, but it's really no big deal. That's why I brew larger batches, to account for losses.
If you don't bend your dip tubes, you won't be able to harvest your yeast because you'll blow it all out before you transfer.

I've been looking into fermenting in my kegs and was directed to this thread. I'm not really interested in a closed system yet so I was wondering if I could just ferment with a sealed lid and just release the pressure relief valve each day. Would that spew krausen out the top? I brew just shy of five gallons so would that be feasible?

zoomzilla said:

I've been looking into fermenting in my kegs and was directed to this thread. I'm not really interested in a closed system yet so I was wondering if I could just ferment with a sealed lid and just release the pressure relief valve each day. Would that spew krausen out the top? I brew just shy of five gallons so would that be feasible?

Click to expand...

In my experience this shouldn't be a problem as long as you use dry yeast and just sprinkle on top. If you use liquid or yeast starter you will probably have too much gunk. Also keep in mind how hard it will be to clean your particular relief valve. Some just can't be totally cleaned. If you want you can just remove the poppets from the gas out and use the gas disconnect without the top or inner workings and run a tube from it into a gallon jug half full of sanitizer. If the insides of these parts get gunked up you should be able to give them a good scrub with a airlock brush.

Also if you let the yeast grow under pressure they might die when you relieve said pressure.

Zoomzoola, you can do it. Just don't ferment more than 4 gallons to leave headspace. Liquid or dry yeast makes zero difference as both will generate just as much krausen. You could use the drops that reduce the krausen as well. You can just leave the pressure release valve open. There's pics here of people having removed it and jammed mini stoppers and air vents into there. Lots of options.

Beersk,
I can see what you mean about harvesting yeast. I generally don't harvest from kegs since I dump hot and there's a lot of cold break and fermentation trub down there. If I want to harvest yeast, I'll use the better bottle on a low grav batch specifically.

Weezy said:

Liquid or dry yeast makes zero difference as both will generate just as much krausen. You could use the drops that reduce the krausen as well.

Click to expand...

If I'm fermenting in a corny, I typically use dry yeast simply because of the very little amount of water it requires to rehydrate the yeast, which in turn is less liquid occupying the corny. In my experience even the most decanted starters of liquid yeast hold quite a bit more liquid which could cause issues. If I'm doing something simple like Cream of Three Crops(the recipe that I easily make the most frequently), I can go about as much as 4.5 gallons, a bit of fermcap, and rehydrated US-05 and not have any blowoff problems.

Thanks masterl - I like your style! I'm North of you by 110 miles (Grass Range), we get to Billings once every month or two - I've got a few cornies and was wondering about using them for fermenting ... your DIY helps a lot, NO more plastic buckets! The wife can have the glass carboys for making wine again! If'ns I get the dough, ray, me, I'll check in with the Pepsi plant about getting a few more kegs! I never thought about using them for storage, I've just been using the food-grade plastic buckets from Lowes. (Note to self: the rats and field mice can't eat thru Stainless!) THX!!

Anyone interested in doing this might also like to take a gander at this:
How to Turn Your Corny Keg into a Fermenter
http://www.cornykeg.com/resources/corny-keg-tips/turn-corny-keg-fermenter/

MT2sum said:

Thanks masterl - I like your style! I'm North of you by 110 miles (Grass Range), we get to Billings once every month or two - I've got a few cornies and was wondering about using them for fermenting ... your DIY helps a lot, NO more plastic buckets! The wife can have the glass carboys for making wine again! If'ns I get the dough, ray, me, I'll check in with the Pepsi plant about getting a few more kegs! I never thought about using them for storage, I've just been using the food-grade plastic buckets from Lowes. (Note to self: the rats and field mice can't eat thru Stainless!) THX!!

Anyone interested in doing this might also like to take a gander at this:
How to Turn Your Corny Keg into a Fermenter
http://www.cornykeg.com/resources/corny-keg-tips/turn-corny-keg-fermenter/

Click to expand...

Thanks for the reply, I've been slacking on my brewing for a few months. Actually when i drive by the Pepsi factory they are not sitting in the yard where they used to be so I'd call ahead. Also the last time i was in there the guy wanted like $40 for them or something, and many of need replacement parts and definitely need a full o-ring change. There may be no more to be had. Best of luck and happy brewing.

tsb22 said:

Another less detrimental option to cutting the diptube referenced multiple times on HBT...bend your diptube. I did this after the first time my diptube clogged, its not very fun. I have bent mine to just below the bottom weld line on the 5gal corney. Doesnt seem to leave much beer behind, just the cold break/yeast. Your results may vary, but if you primarily use the same yeast strains & brewing process the trub line shouldnt vary much.

Click to expand...

Why not just keep the keg upside down so the yeast and trub settle on the other end?

superdave12 said:

Why not just keep the keg upside down so the yeast and trub settle on the other end?

Click to expand...

How would you transfer then? You'd have to tip it back over stirring all the yeast back in. Plus, that'd be a huge pain to clean.

Slowly lay it on its side with the fluid side up and then transfer out with CO2. I don't think it would be hard to clean at all. Just spray with a hose or sink sprayer. I always rinse out and then sanitize by filing with Star San solution and purging with CO2.

Definitely resurrecting an old thread here but a word to the wise... DO NOT Cold crash while still having your blowoff tubing connected. I dumped .5gal of starsan into 2 cornies last night. I completely forgot about the cold pressure drop