So I started lagering with CO2 hooked up - I read this should not be a problem, lagering at 10psi...
So the taste of the S-23 version was a bit "pissy" from the start, but it did get better after 3 weeks lagering. The 2124 was getting nice, had an interesting almost Kolsch type character to it (but not Kolsch - hard to describe), but the hops really came through and added some bitter fuzzyness (I think its the Crystal at 30). Likely that would tone down after some more lagering? The 840 was getting very clean - and only after 3 weeks lagering. More time and I think this along with the 2124 will be very good. The S-23 is bad enough to call yuky.
As luck would have it, my temp controller fell off the side of the deep freeze about just under 4 weeks after lagering started. The temp probe came out of the deep freeze, sending it to a chili -16C. I caught it the day after, not completely frozen, but enough that it would not pour. Opened up the deep freeze and unplugged it to thaw... I did open up the S-23 keg to check for ice which let a lot of the pressure escape and made the beer flat very quickly after putting the top back on. After about 3 days coming back up to temp and unfreezing, I turned the deep freeze back on and closed the door. I'm told that it can be a good idea to add more yeast after freezing as much of the yeast will not revive after freezing. Unfortunately I don't have any more 2124 or 840, and the S-23 I don't really want to "save".
So, now that these are kegged, the 2124 batch seems to have an off flavor of some kind - diacetyl maybe, plus something else. I can't help thinking that maybe the lagering process getting interrupted with a freezing / warming event has caused me an issue. It doesn't seem infected, just that the yeast did something and didn't clean up as it should. A variety of folks have tried it, but didn't seem to know what it was. The 840 is now still cleaner than the 2124, but not as clean as it was before the freezing incident. I really do wonder if raising the temp before lagering if finished encouraged something weird. The S-23 is the same - yuky.