BeerBorg

UPS says my latest Northern Brewer package is due for delivery today. Right now it's minus three degrees. There's two vials of yeast in the package. Don't want that sitting out on the front step for any length of time.

I'd be there waiting for sure. Problem is, is it marked on the package keep warm? If not, it may already be froze from shipping. I hope it's not, good luck!!

Yep. They're froze solid. Are they...toast?

They are gonners. Worst possible weather to ship yeast is the dead of winter or the heat of summer. That's what got me started washing and reusing my favorite liquid strains, to always have some on hand year round.

Give a call to customer service, NB will make it right...

Yup, depending on the percentage of water in the yeast slurry and how long it's been frozen, it could be dead.

However, maybe not...

From Wyeast:

http://www.wyeastlab.com/faqs.cfm?website=1#r30

17. What should you do if the yeast is frozen?

Thaw out in fridge.  Activate and assess the time that it takes to swell.  If there is no activation within 24 hrs, do not use.  If there is activation, make a starter to revive culture.

From White Labs:

http://www.whitelabs.com/faq/beer-amate ... ing-stores

1. The most important rule, keep it cold. Yeast needs to be stored in a refrigerator at all times, 40 F (4 C).  Its shelf life can decrease dramatically when left outside of this range. Too cold is just as damaging as too hot; it should never be frozen. Yeast looses 10% viability each time it is frozen.

ScrewyBrewer wrote:They are gonners. Worst possible weather to ship yeast is the dead of winter or the heat of summer. That's what got me started washing and reusing my favorite liquid strains, to always have some on hand year round.

I'm not quite there yet. Some day though. But your right, Screwy. I should have known better than to order liquid yeast this time of year. UPS left it sitting in either an un-heated warehouse or truck over the week-end. The sad thing is is that NB is less than an hour and a half from my door. I'll go to my LHBS this Friday. Hopefully they'll have what I'm looking for.

Update:

I emailed the folks at Northern Brewer and told them about my frozen yeast. They replied back and said that in the studies that they have done with frozen yeast they have found a viability rate of over 95%. Unfortunately I have already tossed the yeast so I can't prove their theory.

Chuck N wrote:Update:

I emailed the folks at Northern Brewer and told them about my frozen yeast. They replied back and said that in the studies that they have done with frozen yeast they have found a viability rate of over 95%. Unfortunately I have already tossed the yeast so I can't prove their theory.

They might be right on that too. I was watching a show on CNBC called Ultimate Factories the other day. This episode was about Heineken and their main brewery in the Netherlands. One part of the show was about their yeast. They showed some footage of people taking test tubes of yeast out of a deep freezer and showed how it was then "grown" and added into the fermenters. So I guess if huge breweries can freeze it with success, then it would work for us too. Of course, I would guess you would have to thaw it correctly and make a nutrient rich starter for them.

Bummer you already tossed it....did they offer to replace it? Or did they pretty much tell you that you were out of luck?

I read a few years back that yeast can be frozen, but it must be treated with gelatin (?) first to prevent cell wall damage?

Could be FIT....of course that episode doesn't show the entire process, just the guys working with frozen vials.

Just for S-n-Gs, read here: http://www.homebrewtalk.com/entries/freezing-yeast.html