Keg sanitizing/filling process questions

[djsereno91]

I'm making the move to kegging over bottling and I'm looking at the different processes for sanitizing/cleaning. As for sanitizing the keg and transferring from the fermenter, I'm finding two different methods.

The first method being to simply fill the keg with sanitizing solution, drain through the lid, then pour/siphon the beer from the fermenter.

The second method is to fill the keg with sanitizing solution, seal the keg, then use CO2 to push the solution out. Next, siphon the beer into the keg through the out poppet while releasing the pressure through the safety valve. Although more complicated, this second method has the advantages of sanitizing the beer lines when pushing the sanitizing solution out with the CO2, as well as filling the keg up with CO2 rather than air, reducing the chances of contamination/oxygenation.

My question is do any of you use this second method and is it worth the extra hassle? Also, I'm not quite sure but I've read that one 5lb CO2 will last for about 8 batches of beer. If I'm using CO2 to push the sanitizing solution out, does that mean I only would get 4 batches out of one 5lb tank?

 

[microbusbrewery]

The more you use CO2 for something other than pushing beer from a keg, the more you'll use and therefore the fewer number of kegs you'll be able to push per fill. So yes, if you're using it to force carb, push sanitizer, pressure transfer from the ferementer, all these things will use more CO2.

I don't know if you literally meant "pour" in describing method #1 above, but don't do that. Always transfer with tubing to avoid oxidation.

The method I use is completely disassemble keg by removing posts and dip tubes. Clean these parts (PBW or Oxyclean, and a brush), rinse well then soak in sanitizer while I'm cleaning the inside of the keg. After the keg is rinsed well, reassemble and add sanitizer to the keg, close the lid and shake the keg to sanitize the interior. Dump sanitizer (remove lid, invert keg and pour out sanitizer) then rack from fermenter to keg, and finally purge the headspace slowly by ever so slightly pulling on the PRV while feeding CO2 via the liquid post. I forgot to mention I usually naturally condition in the keg so I'll add priming sugar before racking to the keg, so I'm only using enough CO2 to seal the keg.

 

[carvetop]

I'm making the move to kegging over bottling and I'm looking at the different processes for sanitizing/cleaning. As for sanitizing the keg and transferring from the fermenter, I'm finding two different methods.

The first method being to simply fill the keg with sanitizing solution, drain through the lid, then pour/siphon the beer from the fermenter.

The second method is to fill the keg with sanitizing solution, seal the keg, then use CO2 to push the solution out. Next, siphon the beer into the keg through the out poppet while releasing the pressure through the safety valve. Although more complicated, this second method has the advantages of sanitizing the beer lines when pushing the sanitizing solution out with the CO2, as well as filling the keg up with CO2 rather than air, reducing the chances of contamination/oxygenation.

My question is do any of you use this second method and is it worth the extra hassle? Also, I'm not quite sure but I've read that one 5lb CO2 will last for about 8 batches of beer. If I'm using CO2 to push the sanitizing solution out, does that mean I only would get 4 batches out of one 5lb tank?

I use the second method you describe and also use CO2 to push the beer from the carboy to the keg. In my opinion, it is absolutely worth any hassle you may perceive. Furthermore, with my IPAs especially, it has noticeably improved the quality of the finished product.
I don't keep track of how many batches/transfers I get per 5lb tank but it's certainly more than 4. I would recommend having a backup tank ensuring that you'll never run out on game day. I'm paying $17.50 per 5 lb refill and I believe it's worth every penny.

 

[Invertalon]

I just did my first keg yesterday... The day before I did an oxyclean soak and thorough rinse... Prior to filling with beer though, I removed the posts and dip tubes and put into starsan... After a bit of time, reinstalled those components back on the keg and filled the keg 1/3 of the way with starsan. Put the lid and flipped the keg upside down to let starsan get the lid and top of the keg. After a few minutes, poured the starsan back into my bucket I store it in. I then hit the keg with some CO2 via the fluid out post and purged some O2 out...

The keg at this point was (hopefully) good to go and racked the beer into it.

 

[djsereno91]

I use the second method you describe and also use CO2 to push the beer from the carboy to the keg. In my opinion, it is absolutely worth any hassle you may perceive. Furthermore, with my IPAs especially, it has noticeably improved the quality of the finished product.

I don't keep track of how many batches/transfers I get per 5lb tank but it's certainly more than 4. I would recommend having a backup tank ensuring that you'll never run out on game day. I'm paying $17.50 per 5 lb refill and I believe it's worth every penny.

I have one of those big mouth bubblers from Northern Brewer with a spigot on the bottom, so I don't need to push the beer out of the carboy. Although air does come in through the blowoff tube. I suppose I could put a filter at the end of the tube.

 

[carvetop]

I have one of those big mouth bubblers from Northern Brewer with a spigot on the bottom, so I don't need to push the beer out of the carboy. Although air does come in through the blowoff tube. I suppose I could put a filter at the end of the tube.

Sure, pushing the beer with CO2 is never mandatory but any other method will certainly pick up oxygen, the amount of which can be argued extensively. I've become a bit of a freak about oxidation because it is generally the culprit of some less-than-stellar homebrews I've tasted over the years when the brewer seems to have all of their ducks in a row otherwise. Furthermore, it's one more aspect of the process that we can exert control over to make a better product so, in my opinion, why wouldn't we do this?

 

[djsereno91]

Sure, pushing the beer with CO2 is never mandatory but any other method will certainly pick up oxygen, the amount of which can be argued extensively. I've become a bit of a freak about oxidation because it is generally the culprit of some less-than-stellar homebrews I've tasted over the years when the brewer seems to have all of their ducks in a row otherwise. Furthermore, it's one more aspect of the process that we can exert control over to make a better product so, in my opinion, why wouldn't we do this?

So would you suggest hooking my CO2 tank to my blowoff outlet and push the beer out through the spigot? Since gravity pushes the beer through the spigot, seems like I'd need to find the ideal pressure of CO2 so that I'm not pushing the beer out with too much turbulence while also providing enough CO2 to fill the volume left by the draining beer, if that makes sense.

 

[Braufessor]

I use the second method. It is really not more complicated. In some ways, it is simpler. The first 2-3 times you do anything it can seem more complicated, but, as soon as you do it a couple times, it seems very simple.

It does take more CO2. But, it does make for better beer. To my way of thinking, anything that is good for beer is worth a few bucks.

By the way, I have 2x 5 lb CO2 Tanks and 2 x 20 lb CO2 tanks....... 1 5lb tank is not going to cut it if you are trying to use for purging, carbonating, serving, etc.

 

[carvetop]

So would you suggest hooking my CO2 tank to my blowoff outlet and push the beer out through the spigot? Since gravity pushes the beer through the spigot, seems like I'd need to find the ideal pressure of CO2 so that I'm not pushing the beer out with too much turbulence while also providing enough CO2 to fill the volume left by the draining beer, if that makes sense.

This method is a bit different than the one I use so you may have to experiment to see what works. I'm going from a 6.5 G glass carboy with a carboy cap into a sealed, CO2 purged keg.

 

[brewcat]

I use the 2nd method. I have a 20# tank. I don't know if you actually use much more CO2. Charge the tank to 12 psi or so, take it off gas and poor through the tap. I then take the lid off and siphon. No need to go through the out, the CO2 is heavier than the air and will stay in the keg.

 

[doug293cz]

I use the 2nd method. I have a 20# tank. I don't know if you actually use much more CO2. Charge the tank to 12 psi or so, take it off gas and poor through the tap. I then take the lid off and siphon. No need to go through the out, the CO2 is heavier than the air and will stay in the keg.

The "CO2 blanket" is a myth. Although CO2 is a little heavier than air, gases homogenize over short periods of time. Filling the tank with the lid off gives plenty of time for air (and O2) to intermix with the CO2. Once the gases are mixed, they do not stratify spontaneously. If you are going to go to the trouble of filling the keg with CO2, then you should fill thru the liquid out post while the relief valve is open. If you open the lid to fill, then you should be doing multiple pressurize/purge cycles to get the O2 out of the keg to prevent oxidation over time. Check out the video. Br2 has a molecular wt of 160 vs. CO2 @ 44, N2 @ 28, O2 @ 32, and NO2 @ 46. The rate of mixing depends on the weights of the gases, with heavier gases mixing slower than lighter gases. In the video, Br2 completely homogenizes in less than 30 minutes with air. The NO2 (about the same wt as CO2) mixes with air in a fraction of the time of Br2. If you open the lid, you have significant O2 in the keg.

[ame]https://www.youtube.com/watch?v=_oLPBnhOCjM[/ame]

Brew on

 

[Braufessor]

The "CO2 blanket" is a myth. Although CO2 is a little heavier than air, gases homogenize over short periods of time. Filling the tank with the lid off gives plenty of time for air (and O2) to intermix with the CO2. Once the gases are mixed, they do not stratify spontaneously. If you are going to go to the trouble of filling the keg with CO2, then you should fill thru the liquid out post while the relief valve is open. If you open the lid to fill, then you should be doing multiple pressurize/purge cycles to get the O2 out of the keg to prevent oxidation over time. Check out the video. Br2 has a molecular wt of 160 vs. CO2 @ 44, N2 @ 28, O2 @ 32, and NO2 @ 46. The rate of mixing depends on the weights of the gases, with heavier gases mixing slower than lighter gases. In the video, Br2 completely homogenizes in less than 30 minutes with air. The NO2 (about the same wt as CO2) mixes with air in a fraction of the time of Br2. If you open the lid, you have significant O2 in the keg.

https://www.youtube.com/watch?v=_oLPBnhOCjM


Brew on

I don't disagree that O2 and CO2 will mix (i.e..... the "heavy" CO2 won't permanently keep O2 out of an open keg). However...... in terms of what is actually happening in the process of putting beer into a CO2 purged keg:

1.) It takes 5 minutes, not 30 minutes
2.) If you have pushed star san out of a keg and replaced with CO2 it is basically 100% full of CO2. If you take the lid off and immediately start draining beer into the keg...... The volume of the keg is filling with beer and pushing CO2 out the opening..... Any "mixing" of O2 with the CO2 is going to take place at the opening of the keg WAAAYYYYYY before it is going to mix with the CO2 just above the surface of the beer.
3.) Once the keg is full..... and there is perhaps an inch of space left, you put the lid on the keg, pull the relieve valve and repurge the head space with CO2.

This process is absolutely not the same as what that video is showing. Any O2 exposure would have to be extraordinarily minor I would think.

I do the same for the fermenter to keg transfer (from Bottling bucket or SS Brew Bucket)...... I just don't find it works well as the spigot size and the beverage tubing that would fit with a quick disconnect are not the same size..... just as easy to transfer via gravity into a CO2 purged open keg.

 

[ViciousFishes]

I've kegged twice now. I have followed the directions from this excellent video to good effect: [ame]https://www.youtube.com/watch?v=NebEtpoVA2k[/ame]

 

[brewcat]

The "CO2 blanket" is a myth. Although CO2 is a little heavier than air, gases homogenize over short periods of time. Filling the tank with the lid off gives plenty of time for air (and O2) to intermix with the CO2. Once the gases are mixed, they do not stratify spontaneously. If you are going to go to the trouble of filling the keg with CO2, then you should fill thru the liquid out post while the relief valve is open. If you open the lid to fill, then you should be doing multiple pressurize/purge cycles to get the O2 out of the keg to prevent oxidation over time. Check out the video. Br2 has a molecular wt of 160 vs. CO2 @ 44, N2 @ 28, O2 @ 32, and NO2 @ 46. The rate of mixing depends on the weights of the gases, with heavier gases mixing slower than lighter gases. In the video, Br2 completely homogenizes in less than 30 minutes with air. The NO2 (about the same wt as CO2) mixes with air in a fraction of the time of Br2. If you open the lid, you have significant O2 in the keg.

https://www.youtube.com/watch?v=_oLPBnhOCjM

Brew on

I do purge the keg. I didn't really think about the air combining. It doesn't take me very long to siphon, I can still see the CO2. Really though, you'll want to purge anyway because you open the fermenter to air.

 

[doug293cz]

I do purge the keg. I didn't really think about the air combining. It doesn't take me very long to siphon, I can still see the CO2. Really though, you'll want to purge anyway because you open the fermenter to air.

You cannot see CO2. The only thing you can see is condensed water vapor, basically fog.

Brew on

 

[FloppyKnockers]

I use method number three. I throw all the racking tools in the keg filled up half way with sanitizer, depress the out post to get sanitizer in there too, wait a couple minutes then flip it upside down. I collect the few bottles I would need and fill them with sanitizer from the siphon. Fill a few bottles then fill the keg. TA-DA.....BEER!!!!

 

[doug293cz]

...
1.) It takes 5 minutes, not 30 minutes

You need to work on reading comprehension. Bromine is 3.6 times as heavy as CO2. It was completely homogenized in 30 minutes. Mixing begins immediately near the initial separation between the air and bromine. The mixing rate of CO2 is more like the NO2 shown later in the video, which is much faster than for bromine, and takes much less than 30 minutes to homogenize. I pointed all this out in my previous post. Unfortunately, the video doesn't tell us how long the homogenization of NO2 and air required.

2.) If you have pushed star san out of a keg and replaced with CO2 it is basically 100% full of CO2. If you take the lid off and immediately start draining beer into the keg...... The volume of the keg is filling with beer and pushing CO2 out the opening..... Any "mixing" of O2 with the CO2 is going to take place at the opening of the keg WAAAYYYYYY before it is going to mix with the CO2 just above the surface of the beer.

Not much mixing of air and CO2 occurs near the bottom of the keg early in the fill, as you note. What you have to worry about is near the end of filling when there is little distance between the surface of the beer and the keg opening. In a full keg you've only got about 3" or so between the surface of the beer and the keg opening. You have to pull out the siphon tube, and then replace the lid to stop the on-going diffusion. That may only take 30 seconds, but that's enough to get significant O2 into the headspace. Yes, it will be less than 21% O2, but even a few percent of O2 in the headspace will cause oxidation over time. I have read somewhere on HBT that commercial packaging specs call for single digit PPM O2 in the headspace. 1% O2 in the headspace is 10,000 ppm, and thats 21X less than what's in ambient air.

...
This process is absolutely not the same as what that video is showing. Any O2 exposure would have to be extraordinarily minor I would think.

...

Got any data (or links to data), or is it just an unsubstantiated opinion?

Brew on

 

[blizz81]

I'm just starting this venture myself after 8+ years of bottling. Was considering the forced transfer but, as silly as it sounds, I'm not sure if I want to get different carboy caps and racking canes to fit both my glass 6.5gal and plastic 6gal carboys & still not have the "freedom" to tilt and control the racking wand by hand. Figure purging the keg before filling (and possibly as I go) will minimize exposure (far better than bottling to date), but ask me what I think after I try a couple IPAs this way. Of course, the first beer getting xfer'd to a keg soon is a very pale White IPA.

 

[Braufessor]

You need to work on reading comprehension. Bromine is 3.6 times as heavy as CO2. It was completely homogenized in 30 minutes. Mixing begins immediately near the initial separation between the air and bromine. The mixing rate of CO2 is more like the NO2 shown later in the video, which is much faster than for bromine, and takes much less than 30 minutes to homogenize. I pointed all this out in my previous post. Unfortunately, the video doesn't tell us how long the homogenization of NO2 and air required.

Not much mixing of air and CO2 occurs near the bottom of the keg early in the fill, as you note. What you have to worry about is near the end of filling when there is little distance between the surface of the beer and the keg opening. In a full keg you've only got about 3" or so between the surface of the beer and the keg opening. You have to pull out the siphon tube, and then replace the lid to stop the on-going diffusion. That may only take 30 seconds, but that's enough to get significant O2 into the headspace. Yes, it will be less than 21% O2, but even a few percent of O2 in the headspace will cause oxidation over time. I have read somewhere on HBT that commercial packaging specs call for single digit PPM O2 in the headspace. 1% O2 in the headspace is 10,000 ppm, and thats 21X less than what's in ambient air.

Got any data (or links to data), or is it just an unsubstantiated opinion?

Brew on

Just pure, 100% opinion. Nothing what-so-ever to back up my thoughts that filling a completely purged keg with beer, creating positive pressure out, and then repeatedly purging the small head space in the keg at the end with CO2 would result in less exposure to oxygen than the vast majority of home brewers ever attain.

Based on a lot of commercial beer - bottled and kegged - I would guess they are a lot further from the oxygen "specs" than I am.

Depending on what people have for a set up, and what they are working with, different processes are more or less useful to them. For some, your process might be the best. For others, a different process might work well. In either case, neither process is "commercial grade" and both processes are WAY better than just splashing beer into an unpurged, open keg or fermenter. At a certain point, arguing over "my process is 97% right and your process is only 95% right" is self defeating.

Both processes minimize O2 exposure to a very high degree - at a certain point, that degree becomes negligible. More or less so depending on what is being brewed as well. If it is a barleywine or RIS you plan on storing for 3+ years..... then the closer you can come to perfection, the better. If it is beer that is going to be consumed in a relatively short amount of time...... is there going to be a significant impact between 94%-97% perfect?? I doubt it.

Never said it was perfect. Never said it was resulting in 1ppm of O2 in the finished product. No, I am not going to send samples to a lab to acquire "data" for you. (By the way, you don't have any actual data in regard to the results of your process on on finished beer either ..... or if you do, you did not share them). Unless everyone is getting lab work done on their home-brew..... none of us knows "for sure."

 

[bmbigda]

Interesting thread. I have been gravity filling beer into a blanket of CO2 for several years and burping the keg thereafter.

On one hand - I have have kegs last for close to a year without getting noticeably oxidized.

On the other hand - I do wonder if a more oxygen free method could improve the hoppy beers

I know there's plenty of us that brew 10 gallon batches that end up in 2 different kegs. Just sayin

 

[doug293cz]

Found an interesting presentation on oxygen in beer packaging, including data on the importance of TPO (Total Packaged Oxygen) here: http://www.craftbrewersconference.com/wp-content/uploads/2015_presentations/F1540_Darron_Welch.pdf. There's a lot of non-applicable stuff about how to tune an automatic bottling line, so you have to wade thru that stuff to pull out the info on TPO. Maybe the most interesting info is on page 21, where it talks about how many parts per billion TPO will lead to detectable taste degradation with three weeks of room temperature storage.

Brew on

 

[carvetop]

Found an interesting presentation on oxygen in beer packaging, including data on the importance of TPO (Total Packaged Oxygen) here: http://www.craftbrewersconference.com/wp-content/uploads/2015_presentations/F1540_Darron_Welch.pdf. There's a lot of non-applicable stuff about how to tune an automatic bottling line, so you have to wade thru that stuff to pull out the info on TPO. Maybe the most interesting info is on page 21, where it talks about how many parts per billion TPO will lead to detectable taste degradation with three weeks of room temperature storage.

Brew on

Love this. IMO, anything we can do to minimize O2 uptake is worth it. There is also this interesting story regarding absurdly low DO numbers in the Alchemist's brite tanks:
https://byo.com/stories/issue/item/3187-advanced-dry-hopping-techniques

 

[doug293cz]

Love this. IMO, anything we can do to minimize O2 uptake is worth it. There is also this interesting story regarding absurdly low DO numbers in the Alchemist's brite tanks:
https://byo.com/stories/issue/item/3187-advanced-dry-hopping-techniques

Interesting article, except for the nonsense about CO2 blankets.

Brew on

 

[blizz81]

Outside of the scope of our discussion, but not the articles: I like how they say

So how and when is oxygen going to be introduced into your beer after fermentation finishes? There are two principle ways so long as you are using proper brewing equipment and not aging for long periods of time. (post-fermentation additions and racking)

...and completely dismiss homebrewers that haven't made the jump to kegging yet / are bottling, and likely bottling without any CO2 purging involved. I'd think that'd be the most significant scenario for oxidation.