Lagering Question

I've got two corny kegs in the keezer two weeks into their secondaries.

The recipe I went with states that after two weeks to hit the target temp and then two weeks to sit I should take them out of the cold and let them warm up for a few days before bottling.

If I'm just going to serve from the cornies do I need to bring them back to room temp again? Does that serve some purpose in the brewing process?

If you are going to force carbonate your kegs, then there is no need to bring it warm again once its done fermenting. For doing a lager though, you should do a diacetyl rest at the end of fermentation prior to cooling it down to serving temp. So say you ferment your beer at 50F for 1.5 weeks, you should bring it up for 55-60F for a few days for the yeast to clean up, then start cooling it down to serving temperature and you can leave it there.

The reason it probably says to bring it warm I assume is either for a diacetyl rest and/or so the beer is room temperature so the yeast can naturally carbonate the beer if you add priming sugar (whether thats in the keg or in bottles).

Interesting....

The recipe had me fermenting between 47F and 52F. Once the FG was reached it got brought up to room temp for a few days and then put into the keezer and the temp decreased from 45F to 34F over the course of two weeks and then left at 34F for another two weeks.

It sounds like I can just carb and tap and don't need to bring it back up to room temp. Does this sound right?

Yeah, this is my first lager.....I'm a little twitchy about it.

Yea, so bringing it up to room temp for a bit was for your diacetyl rest. Typically you don't need to bring it to room temperature though, 5-10F above your fermentation temperature for a few days is enough (go by taste to see if you taste any before lowering it). Then slowly lowering the temperature over the course of 7 days or so to your desired lagering temp is good. You can drag it out longer if you want.

The only reason you'd need to bring it back warm again is if you needed to bottle condition it since the yeast need to do that at warm temperature (room temp is fine to bottle condition lagers too).

I'd suggest reading the book "Yeast". Has some awesome info on making lagers! http://www.amazon.com/dp/0937381969/?tag=skimlinks_replacement-20