aerate when pitching on yeast cake?

[MrFancyPlants]

I wasn't sure if it was necessary as most descriptions of the aerobic phase in fermentation describe oxygen as necessary for bringing the population up to size, but I've also read something about glycogen storage.

Any real life experience would be appreciated.

 

[ZebulonBrewer]

I would also like to know the answer to this question. I hadn't thought of it, and it's a good one.

 

[KeninMN]

The short answer is yes. Active fermentation depletes sterols. Infusion of oxygen will enable the yeast to synthesize more.

The long answer is here: http://www.danstaryeast.com/articles/using-existing-yeast-cake

 

[uncleleon]

This is along the line of the pitch rate discussion. As many of us understand it, oxygen is crucial to the reproductive/populating phase of fermentation. But, if your pitch rate is high enough that you don't need many more new (daughter) cells, you may not need it. Oxygen affects more aspects of fermentation than we know. I would use gravity/viability/original pitch rate to make the judgement for each beer.

The more you learn, the more you can rationalize those adjustments in procedure. I've seen experiments in inline fermentation. Also remember with pitch rates, bigger is not always better. You may scrub less hops, have fewer esters than you wanted, or have too little body.

These procedures help make up brewing as an art as well as a science. Try and try and try again. Just remember these small differences can greatly affect your beer.

 

[MrFancyPlants]

Thanks for the advice. Can you clarify the hop scrubbing properties of a over pitch?
In this case I'll be doubling a second runnings small beer with an equal amount of fermentables from Bochet to a OG of 1.040.
I have a first attempt at a similar recipe that I haven't tasted but will be kegged shortly, assuming it passes the sniff and taste test. I am shooting for a lawn mower braggot, which is funny because I've never tasted mead or it's variations.
The honey takes so much longer to drop all the way.. The last one took nearly a month to stabilize at a SG of 1.000, but I probably used more like 75% honey fermentables.

At any rate, I thought since it is a similar beer (braggot) it would be a good candidate for pitching on the cake. Maybe I leave a little of the old batch and try not to disturb the bottom when I put the aerated wart in? The original yeast was a English ale yeast that never took off in my 64f corner of the basement so I pitched pacman that I bottle harvested and kept stepping up with several smooth batches of cider.

 

[uncleleon]

Sounds good! The hop scrubbing I've found around homebrewtalk here and there. Post results