Temp / pressure advice

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HopIt

Temp / pressure advice

Post by HopIt » Thu Jan 25, 2018 10:58 pm

My cornies are arriving the morrow (yay), got a heavily hopped pale ale to go in. Thinking about numbers, I am planning to put the kegs to 5/6 psi, hold at 4 degrees in the kegerator and have 6 foot of beer line inside the fridge. I calculate around 2 volumes of co2 in that case which is a fairly low level of carbonation but I'd rather go too low than too high.

Firstly does that seem about right? Also how long will this take to carbonate before I can drink it? Also can I serve at 5/6 psi?

Cheers

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Kev888
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Re: Temp / pressure advice

Post by Kev888 » Sat Jan 27, 2018 12:42 pm

I agree with aiming for this type of modest carbonation, at least as a starting point. It is easier to avoid foaming, and also IMO the force-carbonation charts tend to advise levels that are rather too high for traditional British beers (though if you are going for a US take on things then they are probably about right).

Normally 4c is more of a cold lager temperature, and traditional ale territory is up around 12c or so. Though the joy of homebrewing is that you can tweak things to your own preference, and only you know that.

But the combo of low lager-like temperatures with low ale-like carbonation means a fairly low pressure is needed, and cornies use pressure to keep the lid sealed. Yours may work at 5psi fine, but not all do so you may find that you need a few psi more for reliability. In which case a less cool temperature could help curb increases in carbonation.

It is hard to say exactly how long a beer line you will need to balance the keg pressure, since the relative heights and the type of tap also play a part. Lower pressures are easier to deal with, so things are unlikely to be too critical for you. But FWIW 3/8" line has 'much' less effect than 3/16" line, so if the beer dispenses too fast and your taps are close to the kegs then 3/16" (OD) may be beneficial for some or all of the line.
Kev

Fil
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Re: Temp / pressure advice

Post by Fil » Sun Jan 28, 2018 2:11 pm

assuming you got your conditioning/serving temp from a kegging chart its a good starting point. however in practice it can be a bit more by the seat of your pants, your reg may have a higher than ideal minimum setting you can tweak it too and the gauge may not have a fine enough granularity of scale to let you read the difference between 4 and 6 or 8 psi easily..

on the output side a 6ft length of 3/16" may be a bit on the long side and result in a very slow pour with a 6psi keg pressure, iirc the line is expected to reduce pressure by 1-2psi per foot along its length cumulatively but thats an easy tweak just remember to disconnect the beer line from the keg before you chop it down ;)

but it sounds like you have an appreciation of the influencing factors, its just a matter of discovering how your new kit works all together, and refining the procedure accordingly if necessary..

afaik when conditioning @ serving pressure and temperature as per a kegging chart the conditioning can take a week - 10 days to complete, you can speed this up with regular rocking or agitation of the keg. keep it on gas if you do this tho, you will hear the co2 bleeding in regularly as the shaking works. However dont forget your beer may need some time in the keg to mature too so a race to pour a pint asap may not be ideal, nowt wrong with a sample, but perhaps not a session ;)? i dont have a keg fridge so condition with excess pressure over a shorter period, either way if you get something wrong and under or over pressure or set at a too high or low temp. ITS ALL FIXABLE.

the result of a mix up or error in pressure and or temp settings will simply be an under or over conditioned brew, if under conditioned , tweak the temp down or pressure up to correct,and a good rock/shake can aid this too, and if your brew is over conditioned its a pita but a few shake or rock n vent cycles (off gas) or a lot, will agitate and remove the excess condition eventually..

when first setting low pressures with a regulator, always come back an hour or so later and check up on it as some regs will allow the pressure to slowly creep back up needing a bit of a tweak to knock back down the pressure, if left unchecked can result in highly over conditioned brews ..
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

HopIt

Re: Temp / pressure advice

Post by HopIt » Tue Jan 30, 2018 9:59 pm

Hey, me again. Just another quick question...

I've got my co2 tank attached to some gas tubing with a guest disconnect on the end. I've sprayed Star San and soapy water all over all the threads and see no bubbles. I put the disconnect in a cup of water past the fitting and no bubbles.

I set the pressure to 40 psi (without it connected to anything), then turned the knob on the regulatior anti-clockwise until it was loose. The tank is still open into the regulator at this point.

I left it overnight, and 24 hours later the pressure has dropped to 28 psi or so.

I assume this is not expected? Can you see small leaks using the soapy/bubble method?

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Kev888
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Re: Temp / pressure advice

Post by Kev888 » Tue Feb 06, 2018 2:26 pm

(I assume you mean the regulator (not the CO2 cylinder) was attached to the gas tubing, with quick disconnect on the end).

If you turned the regulator right down, then the pressure in your gas line can certainly drop. In fact, in an ideal world it would drop to match the regulator setting (in this case zero psi), but these regulators aren't often very good at dumping excess pressure, some do it better than others; yours has retained some.

If you were to leave the regulator at a set pressure and turn off the cylinder valve instead, then (if there are no leaks) the pressure should remain stable (unless there is a keg connected, in which case the beer may absorb some gas).
Kev

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