No sign of fermentation after 48 hrs

[Vetal]

I was planning on brewing 10 gallons of a Munich Helles Lager - but can only do 5 gallon batches on the Grainfather. So I did 2 separate batches. The first batch got a 2 Qt Starter of Wyeast 2308 and it took off within 24 hrs in a Grainfather Conical Fermenter. I finally kegged that beer using a pressure transfer kit. The fermenter was "opened" very briefly to attach the pressure kit at the top port and then replaced with a bubbler at the end of the transfer (I believe its a 2" port). Unfortunately - I was unable to get around to the second batch due to a family emergency. For 3 weeks - the fermenter was sitting with the yeast cake in a cool basement closet (~50 F) - completely sealed and unopened. About 3 days back - I finally got around to brewing the second batch. Identical recipe:
10 lbs of Weyerman Premium Pilnser Malt
1 lb of Munich Light
0.5 lb of Carapils.
Step mashed at 145F (40 mins) and 154 F (40 mins) - with mash out at 168F (10 mins). Added Whirfloc and Yeast nutirents (1 tsp) with 10 mins left in the boil. Used a counterflow chiller to transfer the wort to the fermenter (directly onto the old yeast cake). I then used pure O2 via a diffuser stone - 1.5 mins.
It has been 48 hrs since I transferred the wort to the fermenter and I do not see any bubbler activity. I also have a Tilt in the fermenter and I do not see any change in the SG. Any idea on what could be going on? Should I pitch additional yeast or stir the yeast cake with a sanitized spoon?

 

[Bobby_M]

Honestly, I find it very hard to believe that all the yeast is dead after sitting for 3 weeks. I'd pull a sample and measure it with a hydrometer. More often when you pitch on a full yeast cake, the fermentation happens so fast it appears to have not started because it's already finished by the time you look. If it really hasn't dropped any gravity at all, I'd be a little suspect about the wort temp going into the FV. Are you sure it was cool or is it possible it was going in at 100F?

 

[Vetal]

Thanks for the suggestion. The ground water around here in winter is about 50F ... I checked the wort temp using my Thermapen - it was about 60F. I agree - I find it hard to believe that the yeast has become inactive or dead within 3-4 weeks. Never seen anything like this... I am stumped. Maybe I will just pitch another packet of 2308 to save the batch.

 

[odie]

gravity reading? leak?