I have a 1.053 OG Pilsner with 34/70 in the fermenter now. I am going to use the yeast cake to ferment a 1.075ish Helles Bock. I think that will be a fantastic beer to have on tap in early May while I take a bunch of time off to work on our gardens and land.
I have pitched directly on to a yeast cake before but for the life of me can’t remember how I aerated and how it went. I normally use a mix stir before pitching and have a good technique for creating a vortex that really creates a ton of foam. I am curious what other people do in this situation. My gut tells me to drain the wort onto the cake then proceed with my usual method and aerate with the yeast in there. Maybe what gives me pause is I remember when Mark first started promoting the Australian SNS method 
he talked a lot about “sheer stress” with stir plates and this method creates a similar vortex. My guess is it won’t matter for just a few minutes.
What would you do if you were me?
You are best off using only about half of the cake but if you do use the whole cake I guess any kind of shaking/splashing you will do will provide enough aeration for the batch since you won’t be relying on yeast growth as much.
I agree you should use no more than half the slurry. You’ll have so much yeast no aeration will be needed.
Maybe what I will do then is just harvest the slurry like normal. I can save some and pitch the right amount.
Thanks!
I am hoping to brew a 1.068 Maibock this weekend. I am planning to use an L28 Urkel crop I took from a batch of Vienna I just kegged. I collected 350ml of thin slurry that I swirled back up into suspension after filling the keg. I was surprised to see that I only had 100ml of thick slurry after the yeast settled because I was fairly certain that I cropped at least a third of what was left in the fermentation vessel. It is pretty clean yeast. All I can say is that based on the what was left in the fermenter L28 Urkel has smaller than average yeast cells. At 75% AA, the batch definitely reached full attenuation. Until I conduct more research, I am going to adjust my fairly clean thick slurry volume pitching rates to be based on 2 billion yeast cells per milliliter for this yeast culture. I will not know for certain until I conduct actual counts. However, there is more thick slurry in my crop than there was in the Imperial package and Imperial claims 200B cells per package. I rack such that I leave nearly 100% of the hop particulate matter and at least 75% of the trub in the kettle. I do not dry hop, so what is usually left at the bottom of a fermentation vessel is mostly dead and viable yeast cells. I pitched the package of L28 straight into a primary containing 5.25 gallons of 1.056 well-aerated wort (I used my acrylic tube venturi-based aerator). L28 ripped through most of the extract in under 5 days at 54F. I raised the temp to 60F and allowed the batch to finish before lowering the temp to 40F.