Frozen Yeast

[Sethela]

Just recieved a shipment of homebrew goodies that included some of Wyeast's Pacman yeast. Unfortunately the air temperature here in MT is a balmy 0 degrees or so and the package spent a long enough time on the UPS truck that the smack pack arrived a little on the chilly side (frozen solid). Any thought on what I can do to make sure that I can still get some viable yeast out of the package?

[Homegrown Hops]

I would say try to make a starter with the smack pack, or activate and see if you get CO2 production. If you get gas production there are live yeast in there, if not then they all burst.

HH

[Lufah]

I would make a starter and see what happens. I doubt that all the yeast are dead.


Travis

[Sethela]

Thanks, guys
I didn't get much CO2 production overnight when I smacked the pack but I can wait a bit longer. I'll make a starter up today and just for kicks I'll do a dilution series and some plating to find out what the % viability is after freezing. Damn, I'm a geek.

-s-

[Bugeater]

Thanks, guys
Damn, I'm a geek.

-s-

Don't worry, all of us here are geeks in their own wierd way.

Wayne
Bugeater Brewing Company

[Lufah]

Thanks, guys
I didn't get much CO2 production overnight when I smacked the pack but I can wait a bit longer. I'll make a starter up today and just for kicks I'll do a dilution series and some plating to find out what the % viability is after freezing. Damn, I'm a geek.

-s-

Don't feel bad. I really want to know what your results are. Add me to the geek list.


Travis

[Homegrown Hops]

You guys are geeks!

HH

[Spidey]

I make frozen yeast stocks when I rack to secondary all the time. I'm a cheap bastard, and if I can save $5.99, I'll do it. I add equal volume of glycerol to thick yeast slurry and put the tube in the freezer. While the viability may be low (never actually tested this), I've had fairly decent luck growing the yeasts back up to pitching levels using DME starters. And the yeasts still produces the "right" flavors for each strain. I know this isn't the "preferred" way of keeping stocks, but it's simple and has worked for me. Mostly, you want to avoid freeze-thaw cycles. As long as the yeast were just frozen once, I would expect that you could salvage the Pacman yeasts from the frozen smack pack.