Priming with wort/speise, frustration

[McKnuckle]

This is mostly just a vent, but encouraging thoughts are welcome.

I tried something new on my current Pilsner - I reserved unfermented wort from the boil (speise) to prime with.

Here's how I prepared the speise. I drained wort just off the boil to a couple of Mason jars at flame-out. Sealed them, and placed them in my 39F keezer. Proceeded with a fairly standard lager fermentation, three days at 50F, followed by a 2 degree bump each day until 60F. Then I moved the fermenter into ambient temps at 68F for two days. It was done and tasted clean after 9 days. OG 1.049, FG 1.013. Yeast is W-34/70.

This is a 2.5 gallon batch, so I saved a little less than one quart of speise.

When the beer was at FG, I poured the speise into the serving keg, and tossed about 2 Tbsp of fresh yeast slurry in with it. Racked the beer into the keg, leaving nearly all the sediment behind. Purged the headspace with CO2 and left about 6 psi in there to seal the lid. Placed it in my fermentation fridge set to 52F. Attached a spunding valve. I'm planning to adjust it to 18-20 psi once pressure builds.

The spunding valve gauge was at 0 psi within a couple of hours, so I assumed the headspace CO2 absorbed into the beer. At 24 hours, the gauge was still at 0, so I pulled the PRV just to check, and... silence. I quickly opened the lid and generously applied some keg lube to the O-ring, just in case. Sealed it back up.

But now it's been 36 hours and the spunding valve gauge is still at 0. And so I wait... I thought the fresh yeast would have kickstarted re-fermentation by now. It seems to be overdue. Maybe it's another leak - so frustrating.

 

[Dland]

I would suggest pressurizing keg w CO2 enough so the keg lid seals. Also, leave spunding valve off, just check pressure w gauge every 12-24 hrs. That removes two variables, only leaving your PRV, which you should be able to hear if leaking. If no pressure builds after that, yeast probably not starting for some reason.

I carb by spunding almost exclusively, and this works for me, what you are doing is very similar, and how I carbed back when I bottled..

 

[IslandLizard]

What he says.^
It's a common problem, corny kegs won't seal or remain sealed at lower pressures (such as <6-10 psi).
A little deformation of the lid or rim could cause that.
They may remain sealed at lower pressures, once sealed at a higher pressure (>20 psi).

Use a good or new lid o-ring and keg lube. They tend to flatten out a bit when left long in locked position, making a seal harder to achieve next time. Some bounce back to shape slowly after being removing over a few weeks or when left open.

 

[McKnuckle]

Thanks guys. I don't have great luck with spunding so far, despite the fact that it seems so easy in theory. I've spunded too late without enough points remaining, and I've had keg leaks a couple of times now that prevented full carbonation.

Before trying this, every time I've sealed up a keg, I've immediately moved it to my keezer and placed it at serving pressure. So I haven't needed to be aware of, or worry about, leaks under low/no pressure.

I removed the spunding valve, pressurized the keg to 12 psi, and left it sitting outside my keezer where the temp is about 63ºF. So a little warmer too, which I can't imagine is going to matter at this point. I'll check the pressure tomorrow morning.