Pressure fermentation in the same keg that the beer gets served from.

[odie]

do you have any clue as to the cell count? Not that I even pay any attention to pitching calculators, but it looks like a lot less than a 2L starter would produce. LOL.

no clue but it's more than was in the packet of dry yeast I started with. I just did a quick keg burp to pop out some active yeast. I still expect to harvest the bulk of the yeast cake once I actually tap the keg for drinking. I just needed some of the same strain right now for a second beer and didn't want to waste a new package.

Many of the "tutorials" I've read on yeast harvesting and/ washing often show that much or less in the final "product"...that which will be pitched to the next fermenter.

 

[odie]

@odie

I wonder how much pressure a ping pong ball can resist. It coped ok with 15 psi ?

I only did it once. I think it was around 10 psi.

But theoretically, a ping pong ball can withstand unlimited pressure. It's round, so that the forces are applied equally on all sides. Those bathyspheres that divers use to go thousands of feet under water at extreme pressure are round for a reason. A cigar shaped submarine hull will typically withstand only a few hundred feet. Some go a little more but that is classified

 

[VikeMan]

But theoretically, a ping pong ball can withstand unlimited pressure. It's round, so that the forces are applied equally on all sides.

Even assuming that a ping pong ball is a perfect sphere (which it's not), it wouldn't withstand unlimited pressure (theoretically and really). My guess without making all the assumptions and doing the math would be something less than 1000 PSI. Maybe considerably less. Not that it really matters.

 

[odie]

Even assuming that a ping pong ball is a perfect sphere (which it's not), it wouldn't withstand unlimited pressure (theoretically and really). My guess without making all the assumptions and doing the math would be something less than 1000 PSI. Maybe considerably less. Not that it really matters.

I think the PRV would pop long before the ping pong ball. I purge my kegs at 60+ psi after filling. Even the one time I used a ping pong ball. It survived.

 

[VikeMan]

I think the PRV would pop long before the ping pong ball. I purge my kegs at 60+ psi after filling. Even the one time I used a ping pong ball. It survived.

Ah. By "unlimited" pressure, you meant pressure up to and including the ~130 PSI it takes to open a corny keg's PRV. That's probably true.

 

[odie]

Pulled a yeast harvest from a different keg...almost nothing, just beer ??? I tapped almost a pint and let it sit over night. Practically zero yeast. I'm guessing the dip tube is bent or not seated in the middle keg dimple/sump whatever it's called.

The beer sample tested at 1.025 and OG was 1.050 so I guess the yeast is still mostly suspended and still active? It's been going about 2 weeks but it's a lager that was running at 40-45 degrees. I normally do this beer at 50 degrees. S-23 yeast. Gonna bump the temps a bit.

Note to self, insert dip tube and check before filling keg with beer.

 

[Brews and Blues]

Had my first pour from my Black IPA using this method and I was very impressed. It could not have gone better. The beer was beautifully carbonated. Flavor was out of sight. I'm curious to how this holds up over the next 4 weeks or so still being on the trub, but if i don't see any off flavors, i think i will be using this method from now on. I had no idea what i was doing with the spunding valve and it must be somewhat forgiving because the beer had a perfect head. Very aromatic. Not to mention less work

 

[odie]

Reading some other threads...pressure plus cold/lager temps seems to be a double whammy on yeasts...I'm wondering if capping the keg after only a very few days somehow "shut down" the yeast. I really should have been a lot warmer if pressurized it sounds like. Can I either de-pressurize to let it finish? or should I just warm it up to ale temps instead?

 

[Brews and Blues]

Thought I would share a pic of my Black IPA using this method. Super happy with the results. Big thanks to everyone here. I have really enjoyed taking a lot of the advice on this board and its really gotten me into the hobby. My next beer is going to be a pseudo SMASH beer with Light DME and one type of hops, again using this method. First time veering away from kits, which I am excited about. I feel like the only issue i have with this black IPA is the dark LME that was in the kit. I can taste it distinctly in the aftertaste after taking a sip when the air hits my tongue. Departure from all LME i think will up the quality even more.
Also side note, I have yet to have to hit this keg with any CO2. Completely carbed with the spunding valve and pouring beautifully for the time being.