Slow Keg (Forced) Carbonation Issue

[Redhouse Brewing]

Any ideas? I have 2 identical kegs (5 gal). I brewed 10 gallons of an IPA and put 5 into each keg after fermentation (10 days) and crash cooled to 38 degrees for 5 days . I then transferred to the kegs and let them sit overnight at 36 degrees in my keezer. I then set 40 psi on each keg for 18 hrs ( my usual burst method). Then I set to serving pressure ~10 psi for a week. The problem is one of the kegs is mostly ~ 80% carbed but the other one is not. I left the uncarbed keg on 40 psi another 6 hrs and still not carbed. There is some carbination but very little. I recently (about 6 weeks) changed all of the o rings on both kegs and keep them conditioned with keg lube every time I empty them. I don’t believe there is a leak as I just used this keg for an Oktoberfest that was properly carbed. I bottled the remaining oktoberfest (same day) so I could use it for the IPA. I did not burst carb the oktoberfest as I let it lager for 5 weeks. I set 9 psi for the 5 weeks and it was perfectly carbed. Therefore I didn’t notice if the keg had slow carbonation until today.

I do closed transfer so the way I fill my kegs is to weigh the empty keg for a tare (8 lbs empty and 8.2 if I use my keg dry hop tube loaded with hops) and then fill to 50 lbs which gets me to the right level. Both of these kegs were filled with exactly 42 lbs of beer for my normal known fill level so I don’t think one has more head space than the other. I did pull the prv just to see if there was good pressure and there is. I’m at a loss as to why one keg is so slow to carbonate. Both kegs were purchased brand new about 6 months ago from Kegco.

 

[Jag75]

Have you sprayed or submerged to see if there's a leak? What about the gas port , maybe something is partially blocking . Maybe swapping it to a different co2 line.

 

[Redhouse Brewing]

Yes I’ve tried to find leaks but didn’t. I have not swapped different lines but am planning to next time I use this keg. It finally got carbed but took 3 days at 40psi. Still stumped unless it’s my secondary regulator. I have 2 so I will try swapping on my next brew. Thanks for the reply and suggestion!

 

[Vale71]

I'd say there's a 99,99% chance that one regulator is way off. Those mechanical manometers can get seriously miscalibrated if they get bumped one time too many.

 

[VikeMan]

Those mechanical manometers can get seriously miscalibrated if they get bumped one time too many.

IMO, everyone who kegs should have something like one of these (possibly with a better gauge), for miscellaneous pressure checking tasks:

 

[Vale71]

FYI I've replaced all my manotmeters with digital ones, even on the CO2 regulator. The one that came with my SSB Unitank was off by 0.4 bar straight out of the box...

 

[VikeMan]

FYI I've replaced all my manotmeters with digital ones, even on the CO2 regulator. The one that came with my SSB Unitank was off by 0.4 bar straight out of the box...

I own one digital gauge and it's horrible. Possibly bad model or luck of the draw. I've replaced most of my gauges with this one:

 

[Brew_Dude41]

Is your gas in post possibly blocked/clogged?

Just a reach, but something might be in there that is sealing off at a higher pressures.

Like I said just a reach, but i would swap that post and see if that helps at all.