Yeast Harvesting for freeze, before or after fermentation?

[jamesrm]

Hey guys,
About to start a yeast bank, do you recommend collecting yeast (Using liquid wyeast smack packs and some vials of the other brand) before or after fermentation? I have some large starters going, and just wondering if I should pitch and ferment a batch with them first, or harvest before pitching?

I see pros and cons of both methods. By collecting before pitch, I get the purest sample possible. By collecting after ferm, I get a much larger amount of yeast to harvest, but it might be great for that beer style, but not so much another.

Someone with more experience chime in and enlighten us all

 

[Piotr]

I freeze samples directly from Wyeast smack-pack (not smashed!). I hope they are well prepared in the factory for long dormancy, I dont want to spoil them.

 

[T-Hops]

I typically make a large starter (2000ml) with a new vial or smack pack. I decant almost all the beer off, slurry it up and fill my culture tubes. If I am going to be brewing soon and need that yeast I leave some yeast in the flask and make a new starter.

 

[PseudoChef]

I fill 1 or 2 50ml Falcon tubes with my starter yeast before I pitch into the batch I am growing it for. My thinking is along the same lines as your - the yeast is more pure and has not undergone the stresses of fermentation. I only use second gen yeast if I have planned my brews that way - but I never save it for freezing.

 

[fratermus]

When I open the pure culture for pitching into the starter/wort, I use the dregs in the yeast container to plate out and culture.

 

[Hombru1]

I am with T-Hops on this one. I harvest from a starter, it is just easier and cleaner.