Using keg instead of fermenter, equipement ?

[Shaika-Dzari]

Hi everyone!

I'm currently fermenting my batch in a plastic bucket.
It's cheap and I know food grade plastic is technically fine but for me using stainless sound like a far better idea.

My local brew shop sells SS brewtech which look fine but, damn, these are not cheap!
Browsing their web site, I saw a 5 gallons keg 100$ cheaper than the brewtech and thought "maybe I could use it as fermenter".
I usually do 2.5 gallon batch, so a 5 gallons keg would have plenty of headpsace.

After searching here, I found it is indeed possible and people seem to do it successfully.
But what I did not find is how to setup the keg to ferment ? Do I need to buy additional piece of equipment (valve, hose, etc) to use it as fermenter ?


Thanks!

 

[VikeMan]

You'd need to outfit the keg with an airlock/blowoff of some sort. Here's one way...
https://www.amazon.com/Cornelius-Keg-Lid-Secondary-Fermenter/dp/B07F92VZJZ

 

[Shaika-Dzari]

You'd need to outfit the keg with an airlock/blowoff of some sort

If I'm not wrong, there is an "out" on a keg. Would using the "out" with a connector / hose in a mason jar filled with water/starsan also be fine ?
No other modification to do ?
Sound too easy...

If it makes any different, the keg I had in mind is a "Cornelius keg / ball lock / 5 Gallons"

 

[VikeMan]

If I'm not wrong, there is an "out" on a keg. Would using the "out" with a connector / hose in a mason jar filled with water/starsan also be fine ?

Yes, that would work, if you can get an airtight seal between the opening and the blowoff hose.

 

[Shaika-Dzari]

OK, my plan is to try something like that:

Thanks VikeMan, have a nice day!

 

[Ayzala]

If I'm not wrong, there is an "out" on a keg. Would using the "out" with a connector / hose in a mason jar filled with water/starsan also be fine ?
No other modification to do ?

You would want to use the "In" post on the keg. The "Out" has the dip tube that goes to the bottom of the keg, that would be a disaster. The "In" post has a short tube that wouldn't be in the fermenting beer.

Other than that you should be fine.

Good luck.

 

[VikeMan]

One thing... using a quick disconnect, as in the above pic) requires leaving leaving the post and its poppet in place. That's fine, if you keep the batch size small enough (and temps low enough, etc.) to ensure no blow off. Poppets and their corresponding small post openings do not handle solids well and are prone to clogging.

Also, if you're going to do that, the dip tube (and its gasket) needs to remain in place. So use the "in" side and not the "out" side. (The "in" side has the short gas dip tube.)

 

[Shaika-Dzari]

Noted! Use the "in"

I'm kind of drinking alone and try to restrict myself to a couple of beer the weekend. That's why I'm only doing 2.5 gallons batch.
Using a 5 gallons keg leaves quite a lot of space. Is it possible to get a krausen bigger than 2 gallons ?

 

[Ayzala]

Another method would be to pull the keg "In" post and shove in a tube that is just slightly larger OD than the opening. This will eliminate the poppet clogging issue. Depending on the type of beer (how big it is) it may cause a high krausen. I have fermented an imperial big stout with 2 gallons of "space" and needed a blowoff.

 

[McKnuckle]

There are always exceptional situations, but 2.5 gallons in a 3 gallon keg is no problem with respect to krausen. So a 5 gallon keg is entirely a non-issue. Just attach a gas QD to the keg's IN port, attach a blow off tube to the other end, and run the tube into a jar of sanitizer. No mods required, easy as can be.

The most annoying thing about fermenting in kegs is actually racking the beer out! The fermenting part is trivial. If you're not obsessed with O2 exposure, i.e. coming from carboys and buckets, then don't worry about it. Just open the lid, stick your auto-siphon into the fermenter keg, and rack away to the serving keg. Super easy.

If you do begin to obsess about O2, then you'll get into pushing beer with CO2, spunding, pressurized fermenting, and closed transfers. Fun and worthwhile, but not necessary if you're just looking to take it up a notch from buckets.

 

[VikeMan]

There are always exceptional situations, but 2.5 gallons in a 3 gallon keg is no problem with respect to krausen.

Depending on yeast strain and/or temperature and/or OG, 2.5 gallons in a 3 gallon keg could definitely be a problem. Many people have had blow off with setups with headspace percentages that big. It just takes the right (i.e. wrong) combination of factors.

 

[McKnuckle]

Of course you are right about the half gallon of head space not being foolproof. It was meant as a comparative reality check since we're actually talking about 2.5 in a 5'er.

 

[Shaika-Dzari]

If you're not obsessed with O2 exposure, i.e. coming from carboys and buckets, then don't worry about it. Just open the lid, stick your auto-siphon into the fermenter keg, and rack away to the serving keg. Super easy.

I'm mostly a beginner and that's what I'm currently doing with my bucket (fermenter bucket => auto-siphon => bottling bucket => bottle).
I see this solution (fermenting in a keg) has killing 2 birds with one stone: I ferment in a stainless steel container and I get a keg to play in the future if I want to try this instead of bottling.

 

[NGD]

Depending on where your located, you should be able to find 5 gallon kegs for cheaper than $100.

Just a word of warning that it get expensive. I recently bought a 2nd keg and a jumper hose to start spunding and do closed transfers with. I never had any intention of owning 2 kegs.

 

[VikeMan]

Just a word of warning that it get expensive. I recently bought a 2nd keg and a jumper hose to start spunding and do closed transfers with. I never had any intention of owning 2 kegs.

Heh. Me neither. I have 9. With various projects and festival seasons, it's roughly enough.

 

[Shaika-Dzari]

Just a word of warning that it get expensive.

I know, I'm kind of following the same path I guess

 

[apache_brew]

5 gallon cornies are perfect for the batch size you're talking about. Not sure if you have a kegerator already or some fermentation chamber like an old fridge or freezer with an inkbird 308 controller, but if you do, incorporating a cold crash into your fermentation is easy. With respect to the dip tube, floating dip tubes have seem to become very popular now. I see them as very useful in fermenting by racking off the top of the beer and drawing down to the yeast cake without clogging your poppet from the beginning (a tip is before you cold crash or let your beer settle for final racking, blow CO2 down into the beer out line to clear it from any yeast/hops that may have settled into the end of the line when using a floating dip tube. That ensures the initial rack is clear from clogging) ball lock fittings with flare thread connections make it easy to interchange CO2 and beer lines if you need to blow CO2 into the beer out post.

 

[NSMikeD]

Before upgrade from the bucket, quick question, do you have a fermentation chamber? If not, I suggest you focus on temperature control for fermentation which can be a simple as a used mini fridge plugged into a temperature controller.

I brew 2.5 gallons batches and have looking at stainless steel conicals and kegs for fermenting (I have a mini fridge on a controller). . I decided to move from the plastic bucket to clear plastic conicals. One they are inexpensive, but more importantly, I prefer so see what's going on. I find the conical mush easier and sanitary to transfer to the keg. some folks harvest the yeast from the conicals.

Plastic conicals are cheap (I haven't seen a high end plastic for 2.5 gal batches yet) but my logic is that after use I soak them in oxy (usually one step) for a day or two for a thorough cleaning and at $45, not an hardship to replace (or set aside one for a sour etc).

Now that I have upped my game with fermentation temperature (IMO, much more important that what you ferment in) I have been looking at post fermentation O2 control and this where I think, when done properly, kegs and ss conicals have their advantage, especially when dry hopping NEIPAS. I(f you can transfer without getting any air in the fermentor nor the keg, that greatly reduces the chance the dry hops will not oxidize. You can add CO2 into both kegs so that no outside air can get in during the transfer.

I hope this helps

 

[Shaika-Dzari]

Hi NSMikeD,

Unfortunately, living in a small apartment means I can't have a dedicated fermentation chamber (like an additional fridge or freezer).
I use part of a small locker room which stay at 18 - 21 C (65 - 70 F) nearly all year long. I mostly only have the place for the fermenter and a couple of other fermentation projects (hot sauce, sauerkraut, etc).

Being a new brewer, there are so many topics for me to improve (consistency, mash temperature, yeast, water quality, fermentation temperature, etc).
I'm mostly still at improving my consistency and mash temperature...

I agree with you, plastic is cheap and should be fine.
But call it paranoia , but I still feel food is best kept in glass or stainless. That's mostly why I'm exploring the "keg way".

Thanks!

 

[oakbarn]

I brewed lagers for years in a keg. I used the in post method. I bought some of the airliock lids but never used them. I moved on with glycol fermenters but kegs worked fine. Make sure they are clean and never leave one empty and fill with water after bottling or transferring. You can bottle or keg directly from the keg. Just make sure you get rid of about a cup before you move the keg. There is yeast debris at the bottom!

 

[bwible]

OK, my plan is to try something like that:

View attachment 699658

Thanks VikeMan, have a nice day!

Yes, use the gas or in side to vent. See the ball lock connector in the photo? It’s gray. The gray connector always goes on the gas side, so that’s what the person is doing here. The liquid connectors are always black. G = Gray = Gas.

That tube inside is very thin and it would not take much to block or clog that little tube. That’s a concern to me.

 

[Shaika-Dzari]

Thanks for the info bwible!

That tube inside is very thin and it would not take much to block or clog that little tube. That’s a concern to me.

I'm mostly doing small batch (10L) and the keg will be a 19L. So I think there is plenty of head space. Still, I will double check the yeast before in case people are reporting for immense krausen

 

[gonefishin2]

I have been fermenting in kegs and serving from the same keg for about 10 batches now. I like it because I think it simplifies the process and leads to less clean up.

I use a 5 gallon keg, a floating dip tube (clear beer draught system w a filter), and a blowoff tube connected to the gas side. I consistently ferment 4 gallons in a 5 gallon keg. I throw loose hops right into the keg when dryhopping.

Once fermentation is finished, i take the blowoff tube off, put my gas line in place, unlatch the lid of the keg and add about 5 psi. I then use the pressure to ensure a good seal on the lid. I leave on the 5 psi of co2 as i cold crash. I commonly inject gelatin through the gas post using a syringe when its cold enough, then turn the pressure up to force carb.

 

[oakbarn]

Yes, use the gas or in side to vent. See the ball lock connector in the photo? It’s gray. The gray connector always goes on the gas side, so that’s what the person is doing here. The liquid connectors are always black. G = Gray = Gas.

That tube inside is very thin and it would not take much to block or clog that little tube. That’s a concern to me.

I had a major blowout once with tons of krudsen in blow off air lock. I did 4 1/2 gal batches in the kegs and never had any issues with blockage. That being said, I did rarely have a problem where a serving keg OUT had to be cleared by back pressure, but never on a IN.