Maybe the master himself will join in, but let me anser your questions as well as this may lead to an intersting discussion
BrewBlender wrote: -Does this mean that you keep the beer in one carboy for 4 weeks at the same fermentation temps (40-55)? On top of the original yeast?
I think 4 weeks is to long. Especially if you don't have a conical and can remove the trub. Ferment cold until most of the fermentable sugars are gone and your apperatent extract is about a 3rd or a quater of the original extract. Now you can let the temp raise up to the upper 50s or lower 60s. This will scrub diatectyl from your beer and encurage the yeast to finish off the remaining sugars. Now it is time to rack to the secondary and slowly lower the temp to 32-40F (this should take about a week).
The primary fermentation should have taken 1.5-3 weeks depending on pitching rate, yeast strain, fermentation temp and starting gravity. There will be enough yeast in suspension when you rack to perform the "lagering" of your beer.
-Do you do a diacytal rest after the four weeks, before you keg or sometime during the primary within that four week period?
A diacetyl rest is performed at the end of the primary fermentation. But it may not be necessary if not much diacetyl is left over. I like to use it to make the yeast finish the fermentable sugars before I start cooling it down.
-After you keg it, how long should it condition? Is this when you drop the temps down to 32 for the "lagering" stage or was Jamil's 4-week primary part if that "lagering"
as little as 4 weeks or as long as 6 months (example: Oktoberfest). The lower the lagering temp, the longer it takes, but the smoother the final beer will be. I like to lager ordinary low gravity lagers for 6 weeks at about 34-36*F. This gives a nice clean lager.
For my lagers I let them carbonate naturally in the keg before starting the lagering process. This is the traditional German approach as the Reinheitsgebot doesn't allow for artificial carbonation. To do this I can rack to a keg with ~2*P of fermentable extract left. I know the FG of all my lagers as soon as their fast ferment test is done which usually takes 4-6 days. I then attach a pressure gauge and bleeder valve to the keg and monitor the pressure build-up while the beer is finishing primary fermentation. Once I have the desired pressure for the targeted CO2 level, I keep it at that pressure by blowing off daily. I may do a diacetyl rest in the keg before I chill it to lagering temp.
Another way of naturally carbonating a lager would be the use of Speise (left over wort from the bew day) This is added to the keg when the fully fermented beer is transfered. A pressure gauge or measured amount of Speise can be used to set the desired CO2 level.
Kai
