[Steve Ruch]

Which one, if any?

[Visor]

I won't suggest that it's the best, but I have a Marzen in the lager fridge that's been chugging merrily along at 44* on Mangrove Jack's M-76 Bavarian for 6 days now. I've also had good results with 34/70 at in that temperature range.

[a10t2]

That isn't really all that low relative to a traditional lager schedule... I've used 34/70, Wyeast 2206, and US-05 in that range regularly.

[Steve Ruch]

All I have on hand is S-189, but I think I've figured out how to get to the upper 40s.

[hopfenundmalz]

WLP800 is said to be the PU strain. They pitch that at 39F and let it rise if what I saw on the tour is remembered correctly

[Visor]

All I have on hand is S-189, but I think I've figured out how to get to the upper 40s.

   Good ol' '05, it's hard to imagine a more versatile beer yeast. I've never used it below 50, but I have no problem believing it would do it's normal no-fail job in the low 40's.