Stirred Yeast Starter Rest Before Crashing?

Hey BAs,

I was reading through the yeast management section of the latest version of 'How to Brew' and noticed that Palmer mentions that if you are building a starter on a stir plate and propagating for 24 to 36 hours, you should stop the stir bar around 12 - 18 hours in and let the starter finish still for the remaining 12-18 hours in order to allow the yeast to build up glycogen and trehalose reserves in an oxygen free environment before cold crashing the starter. Those compounds help the yeast adapt to the temp crash and new wort environment of the main wort.

Seems to make perfect sense, but this is the first I have heard of this suggestion. Does anyone else practice this method ? I am curious because I currently have a starter on its 18th or so hour and it is still visibly fermenting, ie. you can see CO2 rapidly rising to the top throughout. It really seems wrong to turn off the magnet at this point!

Curious how other brewers feel about this step.

Cheers!

 

I should have titled this thread "Yeast starter rest before cold crash"

Anyone know how to get that changed?

@Ten_SeventySix_Brewhouse - That's exactly how I have been doing it too. My concern would be getting less propagation from turning off the magnet sooner.. but Palmer is suggesting only having it on for half of the duration of the period. Seems counter intuitive no?

 

Tired yeast just after propagating a starter should build up glycogen and trehalose reserves before cold crashing and then adapting to a new wort... Seems like a legit thing to want to happen to me - But I don't really know, just read that and thought, I have definitely never done that...

Of course you can say it doesn't matter, because things have worked out fine before, but lets just say for the sake best yeast health practices , should we really be shutting off our stir plates halfway through?

@Bryan12345 , I'm a verbose SOB

 

Interesting, it’s crazy there seems to be a lot of controversial information in the latest version of How to Brew. The bit about yeast being tired out before floculating, needing several hours to build up glycogen, how you shouldn’t pitch yeast just after high krausen, don’t put your regulator in the keezer etc. There have been quite a few tid bits that have made me say , what ?

 

“There is an approximately 18 hour Window, between peak activity and flocculation, when the east is tired and you shouldn’t pitch it”

That’s all he says about that..

 

@Brewday I know ! The one that surprised me the most was keep your tank and regulator out of your keezer, as condensation ruins them ...