As many of you know, I brew a lot of lagers, but this one has befuddled me.
Been running 835 German Lager X currently. Previous 2 pitches (dortmunder and pilsner) were extremely healthy, fast (<8 days) and flocculent, and sampling has been so great that I am hoping that 835 is made a year round.
Third pitch into an Oktoberfest (600ml Slurry/27 days since previous pitch so calced as 2 weeks ‘old’, 12 gal 1.058 wort) 2 minutes pure O2. 72 hours in nothing. at 84 hours, I gave in and pitched another 200mL. at 96 hours started to see airlock movement and krausen development. it is now pounding away, dropping about 1 plato per day.
I’m not sure what I’ve done wrong here. I’m extremely pissed as the brewday went otherwise perfectly. I am already tentatively scheduling a rebrew in late June or early July, growing some 835 from the 1st fermentation that I saved, in anticipation that this one being completely FUBAR.
With that much yeast and decent oxygen it doesn’t seem like the lag period would be too long. Any chance of thermal or osmotic shock when you pitched? I’m not sure how severe it would have to be, but if you were pitching warm yeast into cold wort maybe it never quite “engaged”?
The other thing that comes to mind is that maybe previous shock or storage conditions somehow caused the yeast to burn up all their reserves (so they had to “refuel” before starting to reproduce)?
Maybe Sacc can throw some better science at this one, as when this stuff matters and when it doesn’t has always been a bit of a mystery to me. I usually just say a little prayer to Ninkasi and hope for the best
harvested the yeast from the pils earlier that day, stored in mason jar in the fridge up until pitching.
thankfully, the fermentation now looks decently strong (krausen formation, airlock activity, etc) so there is a possibility that it might end up okay, but I’m expecting to have to dump and re-do.
That is really weird. How are you measuring your fermentation temps? Thermowell? Temp probe taped on?
Only reason I ask is that maybe the actual fermentation temps are COLDER than you believe them to be due to a whacky miscalibration for some reason. I could see that slowing down your active fermentation time. Just a thought.
had not thought of that - I keep the probe affixed in a insulation pocket on the cone of my fermentor. I also have a thermostrip attached for a belt and suspenders approach. every so often I use my thermocouple to take a reading of the temp and compare to the other two and its usually close - will look at that again later as it has been a while.
The easiest fixer upper is to blow CO2 to the cone of fermentor to put yeast back into suspension.
Now I think there are couple of things about repitching. It takes me up to 6 generations till my new pitch become to be super yeast.
Yeast will consume oxygen is short period of time. I airate wort after HX before it enters the fermentor. It is quite important to airate/oxygenate wort when you repitch. It takes me 3 batches to fill fermentor and they are about 4 hours apart. Each batch is airated.
Last thing is do not ferment too cold. I start at 52F and go up every day.
Now translate it to your system and it should work quite nice. Let me know if you have any questions.
I start WY2124 at 48 degrees for all of my pale lagers, 52 for darker lagers, and don’t have any problems with lag time. It obviously depends on the yeast. In your case, Paul, it sounds like you may have gotten a slurry with more dead yeast/trub or hop matter than you anticipated.
I wouldn’t stress too much about the longer lag though. I bet the beer will turn out fine.
How did this one work out for you? Any revelations as to what you think might have happened? Did you add any yeast nutrient to the boil kettle for your repitched slurry?
