Starter size? For wyeast pack, when solely freezing yeast

[mindless2]

Hey Guys,
I recently purchased 8 packs of wyeast for very cheap because they only have a 2 months left on them.

The plan is to make a starter, then fill up my 50ml tubes with the yeast and glycerin......

A 1 litre starter seems a bit much considering I'm not making a beer.

Would a 500ml starter be ok for this?
Or do I need a 1 litre to propagate the yeast properly??
I hate wasting dme and my canned starter wort..

 

[Cyclman]

I think this starter would be to wash the yeast more than grow it. So I wouldn't worry about size. OTOH, having more liquid may make it easier to wash.

 

[mindless2]

Yes and no, I think.
I'm looking to grow & concentrate, the yeast as much as possible for good viable storage.
remember these packages are already 4 months into the 6 month best before date.... so may need an extra push...
I'm thinking 1litre may be best after all...

 

[PoppinCaps]

If you want a good amount of fresh yeast to freeze, only use a portion of the package in the starter. That way they can actually reproduce. I do this frequently with smack packs, even ones that are over a year old. Just make a starter big enough as needed to fill the tubes you are planning to freeze. For instance, if you want 10 tubes to start 10 new 1L starters, make a 1L starter with the pack. The slurry split to 10 tubes will create new 1:10 dilution starters, which is pretty ideal, even if the viability is decreased.

 

[mindless2]

Thanks for the partial pack tip, I would have never considered that.....
So 1 litre should yield enough for 10 50ml tubes?
Do you freeze in 50ml vials?
25ml of slurry with 25ml of 20% glycol mix??

 

[mindless2]

Thanks for the partial pack tip, I would have never considered that.....
So 1 litre should yield enough for 10 50ml tubes?
Do you freeze in 50ml vials?
25ml of slurry with 25ml of 20% glycol mix??
How long would you let the starter work it's magic? (I'm using a stir plate)

 

[PoppinCaps]

I usually do 5 vials for 700ml of starter, let it finish on the stirplate for a few days, cold crash and decant as much as possible. 10ml slurry per 50ml conical tube plus 10ml 20% glycerine (or glycerol, not glycol). Put them in a glass of alcohol in the deep freeze to control freezing for 24 hours, then store. I'll use one tube to inoculate a starter up to 1.5L.

 

[mindless2]

Thanks again!!
Not sure why I wrote glycol, lol I have glycerine....

 

[mindless2]

I've also read adding ascorbic acid along with a little dme or YPD storage media can increase viability (in the glycerin mix)..
Have you tried this??

 

[PoppinCaps]

I'm sure it would, in mammalian culture it's common to freeze cells in a concentrated amount of serum which high protein content supposedly protects against shear forces caused by freezing. Would this be the same for yeast? I don't know, never did it in the lab, but yeast are heartier than mammalian cells, maybe we just don't care to get super high yields.

 

[mindless2]

fair enough!! they multiply so fast i guess its a non-issue....

I also can't wait to try the agar... i never imagined something i did in university would be useful again!!

Thanks so much for all the input!!