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Pressurized Keg / Flat Soda

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Chuck917

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Hello - I am new to the soda game and hoping this forum might be able to help me overcome some obstacles I have encountered in my pursuit. I have had luck developing recipes and executing them on the 1L level with a carbonation cap but am yet to have any of them carbonate when trying in a 5G corny keg.( I'm using a"Cocktail" Keg w/ down stems on both In & Out & a 20lb co2 tank ) I have tried turning up the pressure, tried shaking them, tried leaving them connected for 2 weeks and in the end I alway end up with soda that blast out of the tap but the liquid itself is still flat. It foams and froths and those sips taste good put when you pour it in a glass the liquid itself is still.

Questions I have based on thing I have read on this forum?

Hose Length? I have read a few post on the length of the tube between the the Keg and the Co2 tank. I am using the standard 3ft or 4ft tube it came with.

Is it the sugar? I use about 1 gallon of simple syrup, 1/2 gallon juice and 3 gallons cold water. I have read about the idea of carbonating the water and then just adding the Simple syrup but I'd rather have the whole drink carbonated.

PSI - I started off around 40 or 50 and after a week turned it up to around 80 and still nothing. When I set the regulator to 1-5 PSI for serving should I bleed the pressure in the Keg first? If not the soda just shoots out and creates a bunch of carbonated foam and yet the liquid in the pitcher is still flat.

Like I said I'm new to this hobby and this site so if anyone can help or direct me towards a resource that might help it would be much obliged!!!

Thanks so much -
 

Longshot_34

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Here’s what I do. I force carbonate @ 35psi for 2-3 days. Bleed the pressure from the keg then serve @ 7-11 psi. One thing I’ve noticed is warm liquid doesn’t seem to carbonate. I don’t have a kegerator, so I put mine outside so it cools a bit.

YMMV
 
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Chuck917

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I live in a Colorado and have kept the kegs outside with temperatures ranging from 20-35 Degrees.
 

doug293cz

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The length of the tube between the keg and CO2 tank is unimportant. It is the diameter and length of hose from the keg to the spigot that is important. This tube has to have a flow resistance roughly equal to the pressure in tank to avoid massive CO2 breakout during the pour. CO2 breakout cases foaming and loss of carbonation in the liquid. Common 3/16" ID vinyl tubing has a flow resistance of about 1 psi per foot, so as a rule of thumb, you need 1 ft of 3/16" tubing for every PSI pressure in the keg. The previous is for beer. With soda, the sugar content probably raises the viscosity of the liquid compared to beer, which will increase the flow resistance of the tubing, and also suppress CO2 breakout to some extent. So, you may need less tubing length with soda. Also, using smaller diameter tubing will drastically increase the flow resistance, but fittings will be hard to find. Flow control taps or keg connections can also be used to create the pressure drop required for smooth serving.

Also, carbonation charts of pressure vs. temperature vs. carbonation level assume that the headspace is 100% CO2. If you don't purge the headspace of most of the air, then your CO2 pressure will be 14.7 lb less than what the gauge reads (the gauge reads the sum of the pressure of all gases in the headspace.) In this case your carbonation level will be much lower than what you expect.

Lowering the pressure to serve will help somewhat with foaming, but CO2 will still want to breakout since the "internal pressure" in the soda, which determines the driving force for breakout, is determined by the carb level, not the headspace pressure. If you lower the pressure to serve, you must remember to put it back where it was after serving, or the carb level will decrease over time.

Finally, keep the soda COLD, the warmer the soda, the more the CO2 wants to breakout, and dissipate, during serving. Also, lower temps also require lower pressures for a given level of carbonation.

Brew on :mug:
 

Bobby_M

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Hello - I am new to the soda game and hoping this forum might be able to help me overcome some obstacles I have encountered in my pursuit. I have had luck developing recipes and executing them on the 1L level with a carbonation cap but am yet to have any of them carbonate when trying in a 5G corny keg.( I'm using a"Cocktail" Keg w/ down stems on both In & Out & a 20lb co2 tank ) I have tried turning up the pressure, tried shaking them, tried leaving them connected for 2 weeks and in the end I alway end up with soda that blast out of the tap but the liquid itself is still flat. It foams and froths and those sips taste good put when you pour it in a glass the liquid itself is still.

Questions I have based on thing I have read on this forum?

Hose Length? I have read a few post on the length of the tube between the the Keg and the Co2 tank. I am using the standard 3ft or 4ft tube it came with.

Is it the sugar? I use about 1 gallon of simple syrup, 1/2 gallon juice and 3 gallons cold water. I have read about the idea of carbonating the water and then just adding the Simple syrup but I'd rather have the whole drink carbonated.

PSI - I started off around 40 or 50 and after a week turned it up to around 80 and still nothing. When I set the regulator to 1-5 PSI for serving should I bleed the pressure in the Keg first? If not the soda just shoots out and creates a bunch of carbonated foam and yet the liquid in the pitcher is still flat.

Like I said I'm new to this hobby and this site so if anyone can help or direct me towards a resource that might help it would be much obliged!!!

Thanks so much -
First, change your gas input diptube to a normal short one. Next, change your liquid hose to a very long length if 4mm ID EVA Barrier tubing.

Qty of 5 if this will get you 26.5 feet. https://www.brewhardware.com/ProductDetails.asp?ProductCode=EVAbarriertubing4mm55

I can make it up with a picnic faucet or recommend appropriate fittings depending on what you already have. I also guarantee it will fix your problem.

Purging out the air from the headspace is also important but you are mostly losing carbonation in the pour.
 

balrog

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Agree with Bobby on the input change. I never understood putting a tube down under the liquid I want to be carbed, except in the singular sole situation of the act of carbonating. After that, putting gas into a tube, at the bottom, underneath the liquid in the keg, to me is like putting a straw into a glass of soda and then blowing into it. It's going to knock gas out of the liquid as it bubbles to the top, cascading effect, massive decarbonization, cats and dogs living together, real wrath of God type stuff.
 
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