Frozen Yeast

[Kevin79]

So I'm halfway through my boil and pulled out my white labs yeast than I just bought this morning out of the fridge to adjust to room temperature. Turns out it's frozen. The liquid is still liquid, but compacted yeast itself is pretty solid, gave it a few gentle shakes and it is not breaking up. So I guess I'm gonna run out to the local wine making store and get some dry beer yeast (that's all they carry) because my homebrew store is just too far away for me to want to drive to again. Anyway, is there any point to pitching the white labs vial anyway for the nutrients?

 

[darylwoodman]

So I'm halfway through my boil and pulled out my white labs yeast than I just bought this morning out of the fridge to adjust to room temperature. Turns out it's frozen. The liquid is still liquid, but compacted yeast itself is pretty solid, gave it a few gentle shakes and it is not breaking up. So I guess I'm gonna run out to the local wine making store and get some dry beer yeast (that's all they carry) because my homebrew store is just too far away for me to want to drive to again. Anyway, is there any point to pitching the white labs vial anyway for the nutrients?

Good question. My first thought would be no, but then could the stressed out yeast cause some off flavors in your beer? If you have the capacity to run multiple yeast starters, you can save it that way. For example, step it up from 100ml starter (24hr) to 250ml (24hr) to 1,000ml (24hr). The problem you have is that you will have no idea what cell count you will end up with. You could still under pitch or even over pitch. Unless you can count the yeast, I would dump it in the trash. Your wort has all the goodness it needs for the yeast. Don't risk the unknown on a 5hr brew day, $40 of consumables, and 3 to 4 weeks of even harder to come by patience. Just stick with the dry packet for now and check your fridge--learn from your mistake. Was it touching the back of the fridge? Stick to placing it in the fridge door--there are no coils there.

 

[darylwoodman]

So I'm halfway through my boil and pulled out my white labs yeast than I just bought this morning out of the fridge to adjust to room temperature. Turns out it's frozen. The liquid is still liquid, but compacted yeast itself is pretty solid, gave it a few gentle shakes and it is not breaking up. So I guess I'm gonna run out to the local wine making store and get some dry beer yeast (that's all they carry) because my homebrew store is just too far away for me to want to drive to again. Anyway, is there any point to pitching the white labs vial anyway for the nutrients?

BTW, I leave my yeast out the day of or the day before (at room temp/pitch temp) so that it is in its log growth phase--that is yeast awake and ready for duty phase). Removing it from the fridge and pitching it will delay fermentation.

 

[d3track]

Shake the crap out of it, put it in your pocket the rest of the brew day to warm it up and agitate it

 

[flars]

According to Wyeast deduct 10% from the viability of the yeast for each freeze/thaw cycle.
Is your yeast frozen or just compacted? If you suspended the yeast before refrigerating it, then it may be frozen, if not then it may be compacted in the bottom of the vial.
Unless your brew is very low OG, and the yeast was less than a week old, a starter would be necessary. With a stir plate you may be able to pitch tomorrow afternoon.

 

[Kevin79]

Well guys thanks for the replies, but I ended up letting it thaw and pitching it after reading some more about the viability lost after freeze/thaw cycles. I'm just gonna hope 10% loss of viability isn't horribly significant. My OG came to 1.060 but it was a sweet stout that included 1 pound of unfermentable lactose so that brought the OG up some. As of this morning it is chugging along just fine so I'm not too worried. View attachment ImageUploadedByHome Brew1423934233.777153.jpg

 

[Kevin79]

Good question. My first thought would be no, but then could the stressed out yeast cause some off flavors in your beer? If you have the capacity to run multiple yeast starters, you can save it that way. For example, step it up from 100ml starter (24hr) to 250ml (24hr) to 1,000ml (24hr). The problem you have is that you will have no idea what cell count you will end up with. You could still under pitch or even over pitch. Unless you can count the yeast, I would dump it in the trash. Your wort has all the goodness it needs for the yeast. Don't risk the unknown on a 5hr brew day, $40 of consumables, and 3 to 4 weeks of even harder to come by patience. Just stick with the dry packet for now and check your fridge--learn from your mistake. Was it touching the back of the fridge? Stick to placing it in the fridge door--there are no coils there.

Oddly enough the yeast was in my fridge door, where I always keep it. I had just purchased the yeast maybe an hour before I started brewing, so it was in my fridge for a little over an hour. I'm thinking the yeast was frozen when I bought it, i didn't really inspect the vial, save for checking the expiration date. I'm betting they had just got a shipment in and the vial had frozen during transport. We have some really cold weather right now in Pittsburgh, PA.

 

[theck]

I used some frozen yeast one time after a local shop said it would be ok to use, ended up being the only batch I've ever dumped.

 

[darylwoodman]

Oddly enough the yeast was in my fridge door, where I always keep it. I had just purchased the yeast maybe an hour before I started brewing, so it was in my fridge for a little over an hour. I'm thinking the yeast was frozen when I bought it, i didn't really inspect the vial, save for checking the expiration date. I'm betting they had just got a shipment in and the vial had frozen during transport. We have some really cold weather right now in Pittsburgh, PA.

We don't really think that the fridge can be a "warm place". Your LHBS has done you a disservice. Freezing yeast in the absence of a cell membrane stabilizer like glycerin will allow the cell wall to break--killing the cell. I would let your LHBS now what happened. Most likely others have reported the same thing. It might be their fridge that is the problem. While you have active fermentation, I hope that it continues down to the required FG without off-flavors. Please follow up and let me know how it tastes.

Good luck-