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Natural carbing in a keg.

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MrFancyPlants

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If I add priming sugar or honey to a (low) pressure fermented keg and seal it up, do I have to worry about oxygen? I know fermentation scrubs oxygen, but i feel like a big part of that scrubbing is the vented co2 taking the oxygen with it on the way out.

I was planning on topping up the keg with distilled water, honey, dry hops, a few cans of nitro cold brew coffees. And sealing it up to target 30-40 psi.

Should I pre-boil the distilled water first. And/or vent the head space?
 

Vale71

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If you open up your keg to the atmosphere you will have massive oxygen ingress. You are correct in your assesment that O2 scrubbing is due to the CO2 venting from the vessel during fermentation. Since when priming you will retain all the CO2 that is further produced for the purpose of carbonating the beer this scrubbing will no longer take place. You can and you should purge the headspace once the keg is sealed again (this will require a rather large amount of CO2) but you'll still be almost completely voiding the advantage of fermenting in the keg.
 
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MrFancyPlants

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Thanks for the response. If I add some extra priming sugar and vent it back down to 30 psi, might I not need to worry about pre boiling the distilled water? How much extra should I add?
I know adding nitro coffee is kind of silly as I was hoping to get some nitro effect by locking it in, but pseudo nitro works ok too (Lower carb but served at higher pressure with a short line). The roasty/toasty coffee note play well with the oak stave in the fermenter.
 

Vale71

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There's no N2 in nitro coffee so you're just adding low-carbed coffee to the mix. Sorry but I don't understand your first question. What do you wish to accomplish by adding more sugar and what has that got to do with pre-boiling water?
 
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MrFancyPlants

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Preboiling the water would knock down the o2 added, but adding extra sugar would allow me to vent and bring it up to desired carbonation level (and exclude the o2).

My last batch got rave reviews from some biased friends. I added boiled honey water (and forgot the dry hops). Because I had calculated the batch strength on 5 gal, but gave it a long boil on a wood stove the initial fermentation was concentarated. Even though I only added enough priming sugar for a light carb, I think diluting the concentration of the batch caused the fermentation to kick off with vigor and I had to vent repeatedly.
Perhaps I’ll try similar this time and I need to dilute or else I’ll be drinking lightly hopped barley wine. I’m using the (Voss I think) kveik, so the whole process has been literally playing with fire, but turning out quite drinkable considering the number of wacky techniques I’ve been playing around with.
 

yowzers

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Yes, I use 2/3 cup of regular sugar to naturally carbonate 5 gallons. If you added more, say 1 cup, you should be able to bleed the headspace a couple times, although it does take a day or so to start building pressure.
 
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MrFancyPlants

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Is there a good reason the gas dip tube in my corny is so long? I would think even for soda that would be a pain to force carb.
Also I got the cheap disconnects at torpedo and the gas’s jumpers seem to be leaking at the connection. Should I clean and lube some o-rings or just spring for the stainless ball-lock connectors?
 

marc1

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Preboiling the water would knock down the o2 added, but adding extra sugar would allow me to vent and bring it up to desired carbonation level (and exclude the o2).

My last batch got rave reviews from some biased friends. I added boiled honey water (and forgot the dry hops). Because I had calculated the batch strength on 5 gal, but gave it a long boil on a wood stove the initial fermentation was concentarated. Even though I only added enough priming sugar for a light carb, I think diluting the concentration of the batch caused the fermentation to kick off with vigor and I had to vent repeatedly.
Perhaps I’ll try similar this time and I need to dilute or else I’ll be drinking lightly hopped barley wine. I’m using the (Voss I think) kveik, so the whole process has been literally playing with fire, but turning out quite drinkable considering the number of wacky techniques I’ve been playing around with.
You seem to be working hard at O2 avoidance, but you'd be losing a lot of your gains by not purging your headspace.

If I were in your situation I would:
1) Purge the headspace 13x at 30 PSI after opening the top.
2) Use a spunding valve to set my pressure where I need it so that I wouldn't have to mess with guessing how much to vent.
 

marc1

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Is there a good reason the gas dip tube in my corny is so long? I would think even for soda that would be a pain to force carb.
Also I got the cheap disconnects at torpedo and the gas’s jumpers seem to be leaking at the connection. Should I clean and lube some o-rings or just spring for the stainless ball-lock connectors?
They don't need to be that long. I've cut several of mine.
 

bwible

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Is there a good reason the gas dip tube in my corny is so long?
The long dip tube is actually supposed to be used for liquid dispense, not gas.

Remember that cornelius kegs were originally used by Coke (pin lock) and Pepsi (ball lock) for dispensing soda at major chains like McDonald’s and Burger King, among many other places that sold soda. They would fill them with syrup, not soda. If you ever got one that still had some syrup in it, as I’ve done many times , you’d know what a chore they are to clean and you have to replace every gasket because they hold the soda flavor.

The syrup from the kegs was mixed at dispensing time with carbonated water that came from another container. They got more servings out of each keg that way so the kegs didn’t have to be changed frequently. Some of those places could go through 5 gallons of soda in 15 minutes. 5 gallons of syrup would probably make at least several hundred, if not a thousand servings I’m guessing.

As an aside, I remember being prescribed Coke syrup by my doctor as a child.

The syrup did not have to be carbonated, and would be more expensive to produce. So of course, they wanted to try to use every last drop. If you look at the bottom of the keg you will also see a small well that the dip tube even sits inside of at the very bottom. Soda syrup didn’t have any yeast or waste at the bottom.

We are using the kegs for something they were not designed for and many are now switching around the parts and using them in ways they were not designed to be used.

You can cut your dip tubes, but then you will not be able to fully drain your keg and you will be left with beer at the bottom of each keg you can’t dispense. You can make them shorter but once you do, remember that you won’t be able to make them longer again unless you buy new dip tubes.

And I’m going to tell you that these kegs are no longer in use by most of the major chains. They have switched to bag in a box systems. These kegs and parts for them are going to become increasingly more difficult and expensive to buy in coming years.

I just bought some floating dip tubes for my kegs. They have a flexible tube attached to a floating ball to always draw off the top. Many of the online shops have them.
 
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grampamark

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Is there a good reason the gas dip tube in my corny is so long? I would think even for soda that would be a pain to force carb.
Some kegs have gas tubes which are 4-5” long. Is that what you are referring to? My understanding is that the longer gas tubes were part of a system which filled the kegs with a predetermined amount of syrup. If your kegs have this type of gas tube you can cut it off. I have mine just long enough to extend through the threaded shoulder which the gas post attaches to; about 3/4” or so.
 

Camelot Legends

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The long dip tube is actually supposed to be used for liquid dispense, not gas.

Remember that cornelius kegs were originally used by Coke (pin lock) and Pepsi (ball lock) for dispensing soda at major chains like McDonald’s and Burger King, among many other places that sold soda. They would fill them with syrup, not soda. If you ever got one that still had some syrup in it, as I’ve done many times , you’d know what a chore they are to clean and you have to replace every gasket because they hold the soda flavor.

The syrup from the kegs was mixed at dispensing time with carbonated water that came from another container. They got more servings out of each keg that way so the kegs didn’t have to be changed frequently. Some of those places could go through 5 gallons of soda in 15 minutes. 5 gallons of syrup would probably make at least several hundred, if not a thousand servings I’m guessing.

As an aside, I remember being prescribed Coke syrup by my doctor as a child.

The syrup did not have to be carbonated, and would be more expensive to produce. So of course, they wanted to try to use every last drop. If you look at the bottom of the keg you will also see a small well that the dip tube even sits inside of at the very bottom. Soda syrup didn’t have any yeast or waste at the bottom.

We are using the kegs for something they were not designed for and many are now switching around the parts and using them in ways they were not designed to be used.

You can cut your dip tubes, but then you will not be able to fully drain your keg and you will be left with beer at the bottom of each keg you can’t dispense. You can make them shorter but once you do, remember that you won’t be able to make them longer again unless you buy new dip tubes.

And I’m going to tell you that these kegs are no longer in use by most of the major chains. They have switched to bag in a box systems. These kegs and parts for them are going to become increasingly more difficult and expensive to buy in coming years.

I just bought some floating dip tubes for my kegs. They have a flexible tube attached to a floating ball to always draw off the top. Many of the online shops have them.
Any issues with the floating dip tubes? I’m interested in replacing the dip tubes in my kegs with these.
 

yowzers

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No issues with the ones from Ballandkeg. I did have an issue with the Torpedo keg floating dip tube I bought first. It would float and I had to add a stainless washer to the end of the tube to keep it submerged.
 
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MrFancyPlants

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I am using the floating dip tube in my fermenting corny only, though I may add one to my larger “brightening” keg at some point, when I brew enough to start a pseudo solera. The gas tube is not four or five inches long, but I would say a good two inches. Long enough that when I tried to top it off to minimize headspace to purge, I ran into issues with hops and the spunding valve.
Great info all around, thanks for contributing?

A couple last queries, but anyone have suggestions about leaky disconnects (I think I’m using the term right)? The kegs themselves seem to be solid, but the connectors seem to be leaking where they attach to the keg. My jumper to vent through the serving keg kept spending all my spund gas. Even the spunding valve is experiencing the same leaking issue if I leave it connected.
I have a 30 and 100psi spunding valves.. anyone have a good 50 psi one? I think that would be ideal.
My first batch of fireside kveik is dropping pretty clear outside in the cold weather. Just a little haze from the honey perhaps.
 

BierHobo

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I'm actually pressure fermenting in my keg and when I went to get a sample to check where things are at, NOTHING! I have the torpedo and I'm assuming it's floating at the top and though it has a screen, it's not working out. Now I'm stuck with having to open something I expected to keep closed up until serving!
 

Tobor_8thMan

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I've naturally carbonated in a corny keg. Please realize you will get gunk in the bottom of the keg similar to the sludge in a bottom of a beer conditioned in a bottle. Each new pour will have a bit of the sludge. Dump it, or, if for yourself, drink it and then no more sludge until the keg sits for a while and the cycle repeats.

This is why folks use a spunding valve. To naturally carbonate a keg.
 
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MrFancyPlants

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Nothing, like no flow? Is there pressure in the keg? Or is your floating dip getting clogged. You could run some gas back through the beer to bust it free. I use the screen around the floating dip and it flows pretty well as long as I cold crash it well and let the hops settle.

I also give it a light swirl periodically when it is cold crashing, to lessen up any hops at the top.
 

BierHobo

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I have a floating dip tube with a screen over the end, so I really shouldn't have any problem unless things are so bad that it's clogged beyond help, even while being on top (besides yeast that is). Definitely pressure, 10psi.
 
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MrFancyPlants

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Definitely send some c02 back through the beer out line.. should get things flowing. And remember the pressure drops when cold crashing.
I have a floating dip tube with a screen over the end, so I really shouldn't have any problem unless things are so bad that it's clogged beyond help, even while being on top (besides yeast that is). Definitely pressure, 10psi.
 
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