lager primary length

[motobrewer]

So, I brewed my first lager on the 18th. Had an extremely active fermentation (pitched 3 L starter of WLP833 German Bock), and I generally check the grav after a week so I checked today. OG was 1.076 and this is at.....1.049. Temps are consistent 50F. Still constant airlock activity.

Is this normal? How long does primary fermentation on a lager take? My ales generally are done after a week, not 47% done. Not that I move my ales after a week....

 

[motobrewer]

follow-up:

should I start the d-rest right now?

 

[Bob]

Dunno. Depends on where you are. You're looking at an FG ~1.020.

I like to start the diacetyl rest somewhere around 75% of full attenuation (in your case, 1.034) or when the gravity gets to within 2 degrees Plato of my estimated FG (in your case ~1.028), somewhere in that range. I let the beer's temperature rise naturally to 60-ish F, leave it there for 12-48 hours - or until FG is reached, whichever comes first - then gradually reduce to whatever lagering temperature I've chosen.

The length of time your beer takes to attenuate is not predicated on anything other than what's going on in the fermenter. Could take a week to get to d-rest gravity, could take four weeks. You just don't know until you build up a baseline of observed data for your brewery. For me, it's two weeks, +/- 24 hours. But then I always use the same lager yeast, so we're pretty familiar with one another.

Cheers,

Bob

 

[Bobby_M]

I typically start the D-rest ramp up at about day 10 but I wouldn't use that benchmark for a big beer like that. I'd say you can expect to start ramping at 14 days and leave it at 65F at least 2 days or until it's dead.

 

[motobrewer]

cheers guys, thanks for the info