Limiting o2 when filling keg

[DonGavlar]

Hi guys,

Kegging my first batch this weekend. After a lot of research I’ve found the best way to fill a keg seems to be pressure transfer. However, I ferment in fermonsters and at the moment I dont have the set up or know of a set up with these FVs to do a pressure transfer. So, ill be racking the beer into the keg via an autosiphon.

Now, is there a method to limit o2 exposure whilst doing this? I.e filling the keg with co2 before racking etc? I’d love to hear some methods of what you guys do. I’m a complete newbie to kegging so detailed explanations of your process would be greatly appreciated.

Thanks

 

[sbsmann]

I dunno about those fancy transfer methods, but I do know I've had no issues simply transferring with my auto siphon and then sealing it up and setting it at carb pressure. Within a week I always seem to have a great tasting beer.

 

[JONNYROTTEN]

^^^Agree with sbsmann ^^^

I've been kegging that way since day one and my beer always taste good. Maybe someday I'll try closed transfers to see what the difference taste like

 

[Yeastieboy]

Agree with comments above. One thing I have recently dabbled with is adding a few ounces of corn sugar during transfer and then letting the keg rest for a week. It’s not ideal if you’re itching to carbonate. However, that last bit of fermentation probably eats up any residual O2 in solution... or so I like to tell myself. It also adds some nice natural carbonation to get the keg started.

 

[acidrain]

I don't agree. Just say'n.

If you want to fill into a keg void of O2 (and you should), simply fill the keg with starsan, connect the keg normally (Co2 and serving faucet) and push out all the starsan.
Then introduce the beer into the keg through the beer-port while using the un-hooked gas-port to allow the co2 to escape.
Once beer starts coming out of the gas-port, stop the flow and block the ports.

 

[Aaron Beers]

acidrain's approach is a good one (though you don't really need to "fill the keg" so much as just put in a little and shake it up). But dongavlar mentioned using fermonsters so I don't think it will work.

Alternately (and not as elegant):

CO2 is heavier than air. Sanitize your keg. Open the top of the keg (presuming you're using cornie kegs), run a tube from the CO2 tank to the bottom of the keg. Dial the CO2 tank to a low pressure and let it run in the keg for a minute or two. This will push out most of the ambient air. Run the line from the autosiphon to the bottom of the keg and start filling. Once the keg is full, close it off and bring it to your fridge. Once in the fridge, connect it to the CO2 again dial up the pressure. Pull the pin on the keg for a second or so to release the gas, wait a few seconds, do it again, repeat a total of 3 or 4 times.

Pulling that pin will force out whatever gas is in the top of the keg. That will purge out most of any oxygen that managed to stay in the keg on each pin pull. By the end of those 3 or 4 times, you'll have reduced the oxygen to a point where it is largely irrelevant.

 

[phyllobeddo]

My method with a Better Bottle is to hook up CO2 to it for a forced transfer to a keg. Sounds like you don't have the hardware to do that yet.

So, you can always fill up the keg with Star San, seal it off, drain the keg via forced CO2 which should leave it mostly full of CO2 and not air, hook up your racking cane to a liquid out post and then start the transfer via auto siphon or however. I open the PRV before starting the transfer. When the transfer is complete, I purge the keg a few times and then seal it off.

As mentioned, you can naturally carbonate in the keg to help scrub some oxygen as well. I generally use about 50 to 55 grams of corn sugar for a 2.5 gallon batch to carbonate around 2.3 or 2.4 volumes. I boil a few ounces of water and mix in the corn sugar and then dump it in the keg after removing the Star San. You do need to open the keg to do this, but oh well. Purge it again if you like. And I never bother to cool down a few ounces of water. A waste of time, really.

 

[DonGavlar]

Thanks for the suggestions guys.

So, you can always fill up the keg with Star San, seal it off, drain the keg via forced CO2 which should leave it mostly full of CO2 and not air, hook up your racking cane to a liquid out post and then start the transfer via auto siphon or however. I open the PRV before starting the transfer. When the transfer is complete, I purge the keg a few times and then seal it off.

I think I'm going to go with this method, it seems the most sound and least work for me. I think ill just drain a keg off star san through the tap by co2 and then hook up a liquid ball lock to the end of my siphon hose and connect it to the out post and siphon in through there. The only thing is I don't know how to tell when the keg is full... I guess I could connect a hose to the gas post and when beer starts flowing out, I'll know its full.

I'll need to start looking into methods of pressure transferring via fermonsters, there must be a way somehow.

 

[Cevan65]

I use acidrain's approach. The purpose of filling the keg with Starsan and then purging with CO2 is that you end up with a keg that is not only sanitized, but truly devoid of O2. Simply "purging" with CO2 will not eliminate all the O2.

 

[DonGavlar]

I use acidrain's approach. The purpose of filling the keg with Starsan and then purging with CO2 is that you end up with a keg that is not only sanitized, but truly devoid of O2. Simply "purging" with CO2 will not eliminate all the O2.

Yeah think this is the approach I'll be taking, thank you guys.

 

[xico]

Boy you are gonna get a ton of varied responses. Truth is, we all find ways to work things out and based on our uses we are all right.

That said, I'm a stickler of avoiding O2 pickup. I don't drink a lot, and some of my beers go to cellar for months. That's where O2 in your beer becomes a problem. If you are sending the keg to crash and carbonation and intend to drink it within a couple months then it doesn't really matter whether you use the auto-siphon.

I do pressure transfers for all my beers and I add dextrose to the bottom of the keg instead of force carbonate. This will scrub the vessel of O2 as mentioned by @Yeastieboy and you will have the yeast carbonate the keg for you. CO2 gas is not 100% pure, and some sources are as bad as 99% CO2. When you are trying to limit oxygen to 12 parts per billion (.000 000 012) having gas at even (.000 1) you are in the parts per million.

It's not a problem if you drink your beer fast, but if you are in the habit of cellaring, plan to go pro, or send to competitions you will notice the difference some months down the line.

 

[brew_darrymore]

I don't agree. Just say'n.

If you want to fill into a keg void of O2 (and you should), simply fill the keg with starsan, connect the keg normally (Co2 and serving faucet) and push out all the starsan.

I have a question about pushing all the starsan. How do you do that? When a keg kicks, I always end up with 2-3oz of leftover beer on the bottom. I suppose when you push starsan, the same will happen and you will end up with 2-3oz of starsan that you simply cannot push out, so you'll rack your beer onto that?

 

[STMF]

I have a question about pushing all the starsan. How do you do that? When a keg kicks, I always end up with 2-3oz of leftover beer on the bottom. I suppose when you push starsan, the same will happen and you will end up with 2-3oz of starsan that you simply cannot push out, so you'll rack your beer onto that?

Turn it upside down for a while, open the prv and take the last stuff out that way.

 

[phyllobeddo]

I have a question about pushing all the starsan. How do you do that? When a keg kicks, I always end up with 2-3oz of leftover beer on the bottom. I suppose when you push starsan, the same will happen and you will end up with 2-3oz of starsan that you simply cannot push out, so you'll rack your beer onto that?

Just like STMF mentioned above, turn it upside down and open the PRV. I didn't think to mention that earlier, but that's what I do as well.

 

[brew_darrymore]

Turn it upside down for a while, open the prv and take the last stuff out that way.

Just like STMF mentioned above, turn it upside down and open the PRV. I didn't think to mention that earlier, but that's what I do as well.

Thank you, guys! Never thought of that

 

[auburntsts]

I have a question about pushing all the starsan. How do you do that? When a keg kicks, I always end up with 2-3oz of leftover beer on the bottom. I suppose when you push starsan, the same will happen and you will end up with 2-3oz of starsan that you simply cannot push out, so you'll rack your beer onto that?

I'd drain it as suggested, but if you didn't drain the last few ounces of StarSan, would you even notice it being that you'd be putting 5 gallons on beer on top of it? I have no clue, I'm just curious.

 

[day_trippr]

Highly unlikely anyone would notice.

Ime if the end of the Out dip tube is full length and properly located so the tip is inside the bottom well, you're not going to leave behind more than a couple of tablespoons of Star San. Ain't nobody gonna pick that up

Cheers!

 

[PADave]

Agree with comments above. One thing I have recently dabbled with is adding a few ounces of corn sugar during transfer and then letting the keg rest for a week. It’s not ideal if you’re itching to carbonate. However, that last bit of fermentation probably eats up any residual O2 in solution... or so I like to tell myself. It also adds some nice natural carbonation to get the keg started.

Exactly my method.

 

[xico]

I've always left the remaining bit in the corny but now I'm going to turn it upside down, thanks for the suggestion! I suppose a coupe psi on it wouldn't hurt either.

I love this forum!

 

[Indian_villager]

Typed this out recently for another user in the PMs hope this helps.

So after some digging I found that the bouncer filters are simply ron-vik filters with their custom logo put onto it. you can buy them for half the price from Amazon.
https://www.amazon.com/Line-Straine...97329&sr=8-3&keywords=3/8"+barb+inline+filter


I have a table that sits about 1' above the top of the keg and the flow is good enough. It will take about 10 mins to drain the fermenter. Could be slower depending on the amount of debris. There have been some occasions where I have had to clear the filter midway through to get it flowing.

Here is my process.

Equipment needed:
Filter with silicon tubing on both inlet and outlet. Liquid QD connected to outlet.
Liquid to liquid QD jumper
Gas QD to rubber bung (3/8" OD tube fits snugly into a standard rubber bung)
Keg A: Keg sitting full of star san.
Keg B: Empty Keg
CO2, Regulator
Fermenter with bottom spigot (spigot should have that little vent hole used to drain the line after the filter is closed, most have this)



I always have a keg sitting full of star san.
I connect the liquid QD to the filter (the QD goes on the discharge side of the filter. )
I open the lid of Keg B.
I connect the filter-QD assembly to the liquid post on Keg A.
I aim the other side of the filter (normally the supply side but here we are filling it backward to purge the unit)
I set my regulator to 10 PSIg
I connect the CO2 to the gas post on Keg A.
I start the flow of CO2
Once the filter is full of liquid i remove the QD from the liquid post on Keg A
I fold over the open end of the tube (supply side of the filter) and close it with a binder clip to keep it liquid full.
I then unse a Liquid to Liquid jumper to connect the liquid post on Keg A to the liquid post on Keg B.
I push all the liquid in Keg A out to Keg B via CO2
Once Keg B starts rumbling (Keg A is out of liquid and sending gas forward) I unhook the liquid QD from Keg A.
I remove the gas QD from Keg A after it has settled at 10 PSIg
Keg A is now empty and has about 10 PSIg of CO2 in it.
I then take the liquid filled QD assembly and remove the binder clip.
Then aim the open end of the tube at the opening of Keg B.
Quickly connect the QD on the filter assembly to Keg A to push the liquid out via CO2.
As soon as the filter is empty I unhook the liquid QD to keep from loosing too much CO2.
I close the open end of the tube with a binder clip again to keep it full of CO2.
I connect my Gas QD - bung assembly to the gas post on the keg breifly to purge the line with CO2 (2-3 seconds will do)
i remove the airlock on my fermenter and put in the bung with the gas line.
I collect my FG sample. This serves to flush out the spigot and draw a slight vacuum on the fermenter.
I connect the open end of the purged filter to the spigot on the fermenter.
I connect the liquid QD to the keg. This will cause the rest of the CO2 in the keg to whistle out of the vent hole in the spigot to flush out the spigot as well.
Once the spigot is good and flushed I pull the PRV on the keg to vent the last bit of the pressure. (dont want the pressure popping the top of the fermenter)
I open the spigot to begin flow of beer.
I connect the gas QD to the keg.
As the liquid fills into the keg the CO2 in the keg will now replace the liquid in the fermenter.

I know the process seems wordy but in practice setup takes no time.
It is absolutely critical to purge the filter well because otherwise it will sit full of O2 and then will cause great mixing with the beer as it is flowing causing unwanted oxidation.

 

[jturman35]

How are you guys not over filling your keg? The only way I know to do a closed transfer Is if you cold crash. You can see the sweat from the cold beer line on the side of the keg. The problem I see is you can I introduce oxygen during cold crashing. I bought everything to perform a closed transfer but just decided to run the hose to the bottom of the keg so I could see the level as I filled the keg.

 

[xico]

I usually attach a line off the gas port into a little blow-off. Once beer starts to run, I switch the CO2 line to the gas port and push out a pint/half liter.

 

[day_trippr]

How are you guys not over filling your keg?[...]

Net Weight...

Cheers!

 

[Indian_villager]

How are you guys not over filling your keg?

Vol markers on fermenter

 

[jturman35]

Vol markers on fermenter

Yes but to be exact you have to account for trub loss. I like the idea of having a hose connected to the gas side. This makes sense. Weighing seems hit and miss? I’m not sure if all beer weighs the same, never tried this.

 

[day_trippr]

All beer does not weigh the same, but fortunately that is accountable via simple math: 8.345 * OG pounds per gallon.
I Tare my digital scale with the sealed empty keg and lines attached, then fill until I hit what five gallons of that particular beer should weigh.

For a more accurate calculator, contact @kaljade. He has a spreadsheet that includes temperature, altitude and carbonation level. Combined they can shift the solution by up to ounces...

Cheers!

 

[Indian_villager]

Yes but to be exact you have to account for trub loss. I like the idea of having a hose connected to the gas side. This makes sense. Weighing seems hit and miss? I’m not sure if all beer weighs the same, never tried this.

Toss a quart at a time into your fermenter and mark it with a sharpie. With better graduations you can estimate the trub volume close enough.