Yeast has frozen during transport. Still good?

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beauvafr

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I had a US-05 solid yeast as long with a WLP 007 liquid yeast. The liquid got frozen. I could see a big lump of yeast in the WLP007 tube.

Are they good ?
 
The 05 is probably just fine. For the 007, a lot of the cells were probably damaged, but you could maybe make a small starter to try to save whatever cells are still alive. Liquid yeast doesn't do well with freezing, unfortunately.
 
A friend of mine had a vial of White Labs yeast freeze. He pitched it without making a starter and it didn't ferment at all.
 
The liquid on top of the yeast froze? Or was the 007 a solid clump that resist separating after being shook up? 007 clings together till it is room temp and shook up a bunch.
 
I'll probably do a 2L starter.

I'd start smaller, like 250-500ml even, just to step it up slower. Then up to 2L. That's just my opinion, but it stems from this mentality: You want to grow healthy yeast if there are any left alive, and there is no telling how many viable cells you have right now. Most probably died from ice crystals piercing them. A smaller starter will encourage growth from the remaining survivors (assuming there are some) and it will be at a rate that hopefully won't add additional stress.

Edit: Just read poptart's thread. That 1 cup starter looks like a good starting point.
 
Reportedly, mangrove jack m07 is a dry wlp007 strain. Was wondering if this is confirmed. I used on last batch. It worked spectacularly and flocked hard, fermented fast.

From what I understand, some yeasts are banked in deep freeze. These are not intended to be pitched directly into wort though. However, a pitch able vial is going to have significantly reduced viability. Cell count is same, but some to lots are probably dead non viable cells from the freezing. I would recommend making a starter, and if you can do it, do a cell count and viability assessment. Otherwise you are probably better off to see if the place you purchased from will refund or replace the yeast. If you're really intent on that strain, you might try the mangrove jack dry yeast. I do not think that dry yeast will affected as much or if at all by a brief dip below freezing temps.

I have the opposite problem in FL- cooked yeast!
TD
 
I never posted about it because there was already a lot of information, but a few weeks ago while going through my fridge it turns out I had frozen the last of my Conan yeast (YG001). I was pissed because I had big plans for it and didn't want to spend another $15 (I'm being cheap lately).

Luckily it looked like the yeast itself was not solid, like the liquid on top had frozen but not the yeast itself. So I made a 1 L starter, but retained 750mL of that in a jug. After 2 days I barely saw anything, so little that I thought I was deceiving myself. But I figured, what the hell, might as well toss in the rest of the wort. Sure enough the next day I had a nice krausen on top. It smelled right, so I am hoping a few extra hearty yeasts made it through. I probably ended up with about 150-200B cells.

I doubt the yeast will be exactly the same as it was before. But who knows, it might be even better!

Point is: if you have the time and want to try, go ahead and see if you can revive it. If you have to order a replacement ASAP to get it in time, do that. Don't bet on the yeast being viable, but if you want to go ahead and try just for fun.

Side note: I will be using this yeast for an IPA that will be called Frankenstein IPA because the yeast was dead.
 
What makes you believe the yeast froze? I think that yeast clumps anyway. make a starter and find out.

The S-05 will be OK. Since it is dry, there is no moisture to rupture the cells.
 
I had heard that too.

I had heard somewhere on HBT that the mangrove jack M07 is same strain as wlp007. I am not sure if its true or not. Was wondering if anyone could confirm. Certainly behaved more like wlp007 than s04. Drier finish, however I mashed very very low.

Regardless I liked it in this one batch. Will need to use more and gather some feedback from other users.

Is there a dry version of wyeast 1099?

TD
 
What makes you believe the yeast froze? I think that yeast clumps anyway. make a starter and find out.

The S-05 will be OK. Since it is dry, there is no moisture to rupture the cells.

You may be right, i heard so too. My starter is ongoing. No activity, and 24 hours passed. But I am gonna wait and see. Maybe doing a second stage.

By the way, when I mixed the liquid in the vial container prior making my starter, it mixed but the final liquid looks not fully mixed.. still clumpy. Like this :


IMG_2626.jpg
 
Chris White (White Labs) says (via The Session) that freezing a vial will cause a 10% drop in viability. The issue he said is knowing if it has frozen and thawed more than once (that 10% drop for each cycle), but in general just account for a 10% drop in viability based on the date packaged.
 
By the way, when I mixed the liquid in the vial container prior making my starter, it mixed but the final liquid looks not fully mixed.. still clumpy. Like this :

That's a good picture of what WLP007 looks like in a vial that has warmed up to pitch temp and shaken. I always think it looks like egg drop soup when it starts to flocculate while running on a stir plate.
 
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