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can a keg get overcabed being too cold?

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bracconiere

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so i had a keg at around 42f, poured great at 10psi with 10' 3/16" line. but at 10psi and my back keg being at like 35f, i'm getting too much foam?

i know my brain is pudgy and i'm stumbling. but that half ass goes against the warm tap lines thing.

i carbed both kegs to 1.5oz's. but did make the mistake of hooking the gas line to the front keg, before it settled.


(been looking thinking of asking @doug293cz how much a pint of co2 at 50psi weighs, bout how much head space i leave in a full keg....honestly, thanks already doug! i just realized i know it now! when i purge my kegs it goes down like 0.5oz every purge! so it's over carbed!)


i guess that makes this post more suitable for mindless mumbling, lol i'll cut and paste it there!
 

Dland

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Being one of the more frugal brewers, I'm supprised you purge your kegs w tank CO2. Just hook to blow off tube to kegs you are going to fill next during active fermetation, it is easy to ccompletly purge two kegs w a 10 gallon batch's CO2.
 
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bracconiere

bracconiere

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Being one of the more frugal brewers, I'm supprised you purge your kegs w tank CO2. Just hook to blow off tube to kegs you are going to fill next during active fermetation, it is easy to ccompletly purge two kegs w a 10 gallon batch's CO2.

honestly, watching the scale go down when i'm purging that's something i'm definatly looking into! at 50psi purging costs me damn near an ounce!


and to finish up the thread, i remember a post by the local kegging master @day_trippr , pulled my keg out and check the dip tube o-ring, it was like in two pieces. replaced it, and first pour is perfect! it's nice having people to talk to!

edit: and dland, i know you're trying to hurt my feelings...but honestly, now your just giving me good ideas! got me thinking, maybe closed transfers might save me on co2, but i don't give a f about o2! i could like pressure ferment, closed transfer, and wouldn't waste an ounce of co2! wonder how i could set it up cheap?
 

doug293cz

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so i had a keg at around 42f, poured great at 10psi with 10' 3/16" line. but at 10psi and my back keg being at like 35f, i'm getting too much foam?

i know my brain is pudgy and i'm stumbling. but that half ass goes against the warm tap lines thing.

i carbed both kegs to 1.5oz's. but did make the mistake of hooking the gas line to the front keg, before it settled.


(been looking thinking of asking @doug293cz how much a pint of co2 at 50psi weighs, bout how much head space i leave in a full keg....honestly, thanks already doug! i just realized i know it now! when i purge my kegs it goes down like 0.5oz every purge! so it's over carbed!)

i guess that makes this post more suitable for mindless mumbling, lol i'll cut and paste it there!
Sounds like you solved the foamy pour on the colder keg (if I read one of your subsequent posts correctly.) Bad dip tube "O" ring. Correct?

1 volume of CO2 is 1.977 g/L, 0.264 oz/gl, or 0.033 oz/pint. So, 1 pint of CO2 at 0°C (32°F) and 1 atm pressure (14.7 psi) weighs 0.033 oz. At 50 psig the CO2 absolute pressure is 50 + 14.7 = 64.7 psia, so at 32°F and 50 psig, 1 pint of CO2 would contain 64.7 / 14.7 = 4.4 volumes or 0.33 * 4.4 = 0.145 oz.

At 42°F (5.56°C) and 50 psig, 1 pint of CO2 weighs:
0.145 oz * 273.15 / (273.15 + 5.56) = 0.142 oz​
A 5 gal ball lock corny has a total internal volume of 5.3 = 5.35 gal (at least mine do), so with 5 gal of beer the headspace would be 0.3 - 0.35 gal, so let's call it 0.325 gal or 2.6 pints. At 50 psig and 42°F, the headspace would contain 2.6 * 0.142 = 0.369 oz of CO2.

Now if you shook a keg with 5 gal of beer at 42°F at 50 psig of CO2 until the keg took up 1.5 oz of CO2, then the beer would have absorbed 1.5 oz - (0.369 oz - 0.084 oz) = 1.215 oz. You would have added 0.285 oz of CO2 to the headspace that contained 0.084 oz before you pressurized to 50 psig. (1.215 oz / 5 gal) / 0.264 = 0.92 volumes of CO2 added to the beer.

If you did a non-pressurized fermentation (with airlock) at 68°F, the beer would have had a residual carb level of 0.84 volumes. Adding 0.92 volumes (by burst carbonating) would bring the total carb level up to 1.76 volumes.

The equilibrium carb level at 42°F and 10 psig is 2.21 volumes, so after your burst carb session you are still 0.54 volumes below the equilibrium carb value.

Your keg at 35°F and 10 psig will eventually come to equilibrium at 2.52 volumes.

Hopefully this answers your question, but even if not, you will have a few hours of entertainment understanding the math.

Brew on :mug:
 

Dland

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Not trying to hurt feelings, just trying to help, I just started purging w fermentor CO2, ,,,well, not that long ago..., and look,...^^^ here is Doug to help some more!
 
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bracconiere

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Hopefully this answers your question, but even if not, you will have a few hours of entertainment understanding the math.
a few hours of remembering when i was in school to simplify! i'm going have to read that a couple times. appreciate the effort typing it for me!


Sounds like you solved the foamy pour on the colder keg (if I read one of your subsequent posts correctly.) Bad dip tube "O" ring. Correct?
i think so? i got a good pour, took a nap, got another good pour. then when i filled my glass got half foam. dumped it, and second pour was fine? but my lines and keg read the same temp with my IR thermometer?


when i was changing the o-ring i noticed my dip tube had a bend in the flare? could that be letting co2 into the QD? the o-ring definatly was shot! split down the middle horizontaly.
 

doug293cz

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a few hours of remembering when i was in school to simplify! i'm going have to read that a couple times. appreciate the effort typing it for me!




i think so? i got a good pour, took a nap, got another good pour. then when i filled my glass got half foam. dumped it, and second pour was fine? but my lines and keg read the same temp with my IR thermometer?


when i was changing the o-ring i noticed my dip tube had a bend in the flare? could that be letting co2 into the QD? the o-ring definatly was shot! split down the middle horizontaly.
Yeah, a deformed flare could affect the seal.

Brew on :mug:
 
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bracconiere

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Yeah, a deformed flare could affect the seal.

Brew on :mug:

damn! once again HBT has me wanting to drink more, to f around with stuff like this!

is there a good method to fix it? both my pin locks are diferent heights, so i'm not even sure how i'd replace it?

another thought, being i only have 2 pin lock kegs, and don't use my pin lock bev connect offten, could it be dirty, and need to be broken down and cleaned? i rinse it after i use it but then it just sits...
 

doug293cz

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damn! once again HBT has me wanting to drink more, to f around with stuff like this!

is there a good method to fix it? both my pin locks are diferent heights, so i'm not even sure how i'd replace it?

another thought, being i only have 2 pin lock kegs, and don't use my pin lock bev connect offten, could it be dirty, and need to be broken down and cleaned? i rinse it after i use it but then it just sits...
I always break my keg posts (all ball lock) down for cleaning every time I clean a keg. It's not that hard to do, and I consider it cheap insurance.

Brew on :mug:
 
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bracconiere

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@doug293cz well i was pouring over your post, i did learn the diference between psia & psig..

and i live at 4500ft, so the absolute pressure would be 2 psi less if i remember correctly....? but that's a bit much for burst carbing accuracy!

(and pfft :roll eyes: it only took me 15 minutes! lol :mug:

and yeah i'll have to revisit the post again! ;))
 
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