Freezing Yeast

I would like to know how successful freezing wyeast is and your ideas on how you guys do it.
It costs me about $16.00 for a 50ml wyeast over here so it brings the cost of my
brews up bigtime. if i harvest yeast from my fermenter into jars and fridgerate it and it only lasts a few weeks it puts alot of pressure on my brewing.
Hope you guys know where im coming from
Help!!!
Daza

Daznz

I found this link:
http://www.schwedhelm.net/brew/yeast_harv_freeze.html

Never done this myself but I hope it helps.

-K9

I've kept harvested yeast in the fridge for several months with no ill effects.

Slow freezing will rupture the yeast's cell walls I think, if you can work out a way to cryogenically freezing your yeast instantly then I think you'll be ok :cross:

Or you could try gylcerol....

http://www.ipass.net/mpdixon/Homebrew/Freezing Yeast.htm I have been using this method for freezing my yeast (all lager strains so far) and as of yet haven't had an oppertunity to thaw and reuse so I guess it is still in the experimental stage yet.
In the meantime I store yeast cakes in the frigde under airlock for up to 4 months and just pitch to a big starter to get it going again.
Cheers

Thanks for the links and help guys ... well the guy in the first links has used yeast at 9mths old so it must be a good method ill give that a shot
Thanks Daza

I've seen Alton Brown on Good Eats use dry ice to quickly freeze strawberries and such to keep large ice particles from forming and breaking cell walls. I'm not sure if yeast would survive it. Though I think if you put the yeast in a regular freezer you have some annealing of the small ice particles which will, over time, kill the yeast. I don't have yeast starter equipment, so I can't try to prove or disprove that hypothesis with yeast.