Cold Fermentation method keeps failing me (stalling)

[Brandon]

[Bryan R]

Seems like! It is! We verified it with DO meters.

[Nick_D]

[lupulus]

Thanks Nick. May be I should have clarified that I am not advocating transfering to the keg at the end of lagering. I am = convinced the final transfer should happen when yeast is still reasonably active and can scavenge any oxygen incorporated during the transfer.
I pitch cold, around 6-7C, I warm it up to 10C (with Augustiner yeast, 9C with Andechs or Ayinger), keep it there until 1P from predicted final gravity, transfer it to the final keg, keep it at 12C for 3 days and then gradually ramp it down to lager temp at about 2C per day. I check pressure after reaching 0C, and if needed, I connect the spunding valve to keep it at about 1 bar.
I do not think this is better than what the main group is doing (maybe it is worse), but I think I would have to pay much closer attention to yeast management and do at least some rough FAN calculations if I were to do ramp down temp at the end of fermentation.
It would be so nice to test side-by-side and see if there is a difference.

[Nick_D]

[Big Monk]

I wise man once told me that cold ferment lager brewing takes, "Patience and a shit-ton of yeast".

Assuming that you are doing as some of the members here have described, i.e. pitching lots of yeast and oxygenating your repitched with pure O2, could it be that your a bit impatient?

Members here have described waiting a few weeks to eek out the final gravity. That's with exemplary yeast health and temperature management, both of which you've questioned yourself on a few times in this thread.

Assuming patience doesn't factor in here and you have a genuine stall, maybe a review of your yeast management, oxygenation and transfer methods is warranted.

[Nick_D]

[Big Monk]

I'm probably not the best person to ask on yeast propagation. I'm a small batch Brewer and have never used starters.

As such, I'll be following Bryan's multiple packs initial pitch/oxygenated slurry repitch lead.

I would think that if your FFTs are finishing at a lower gravity then you have a yeast pitch/health issue or a temp management issue. Those 2 things seem to warrant the most attention.

[Techbrau]

Repitched slurry is full of strong, proven cells but is also basically oxygen starved. So you need to be absolutely sure you are giving them enough oxygen at repitch for them to rebuild their cell walls, because if you don't then they will not be able to multiply as much as you need them to, and their cell walls will be weak and leaky, resulting in a bad ferment.

One technique reccomended in Narziss and Kunze is to mix repitched yeast with freshly propagated lab yeast. Try a 50/50 mix along with sufficient aeration at pitching.

Another schedule you can try is a variation of the warm ferment. Pitch at 6c, ferment at 9c, then at 50% AA start cooling back down to 6c. Rack when you are about 3 gravity points above your expected FG, and hold until you are within a point or less of FG before cooling again to 2-3c, where you can hold until the beer is clear.

[Nick_D]