can White Labs vials be frozen?

I am wondering if a new white lab vial can be frozen (is there glycerine in the vial to protect the yeast?) The reason I ask, is that I think it would make sense to just take a sample from the orig vial, make a starter and pitch that. Then throw the remaining vial back in the freezer. This way you could probably get 10-20 gen 0 cultures, and don't have to worry about mutation or yeast washing/harvesting.

-J

IIRC there is only yeast and nutrient in the vial...nothing to prevent the yeast from getting zapped when frozen.

I seriously doubt it, otherwise they'd probably advertise it that way.

In theory you could just pour out some of the yeast slurry and add some glycerine to the tube in its place... But I have not frozen yeast before - can you really just grab a sample and chuck the rest back in the freezer? Don't you have to thaw it each time, and wouldn't that be really hard on the yeast?

No, they can't. You'd have to do as Funkenjaeger says and add glycerine. That's how I store my washed yeast if I'm looking to store it long-term.

Thanks... This is how I store my yeast as well, and I was just thinking that it would be less hassle to just freeze the orig vial. It would be simple enough to add 1/2 glycerine to the vial though.
-J

Rhoobarb said:

No, they can't. You'd have to do as Funkenjaeger says and add glycerine. That's how I store my washed yeast if I'm looking to store it long-term.

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Do you sterilize the glycerine?

Dr Vorlauf said:

Do you sterilize the glycerine?

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I never have... I just use what is in the first aid section of my pharmacy. I'd assume it's sterile.
-J

you would need to sterilize the glycerine, and adding enough glycerine to make a 50% solution is too much. 15%-20% of the total solution is all you want. like funkenjaeger said, those yeastys wont be very happy being frozen and thawed all the time.

SenorWanderer said:

you would need to sterilize the glycerine, and adding enough glycerine to make a 50% solution is too much. 15%-20% of the total solution is all you want. like funkenjaeger said, those yeastys wont be very happy being frozen and thawed all the time.

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How do you sterilize the glycerine? Do you boil it? Could you fill some tiny masson jars and sterilize/can it in a pressure cooker?

Yes, technically you should sterilize the glycerin. For all practical purposes you really don't need to, at least in my opinion. The Glycercin you buy at the drug-store will come sterile up until you open it, and the same goes for opening the vial of yeast.

Although it is possible that something might float into the vial while it is opened and contaminate the culture, it is extremely unlikely given the time-frame in which the frozen stock of yeast will continue to be viable.

Whoever brought up the fact that the freeze/thaw is the bigger issue is correct. 10-20 uses out of a single vial is probably not going to be possible...maybe 3-4 tops.

so split it up into different vials before the first freeze. This whole idea makes perfect sense to me. liquid yeast is expensive, but if you could make it last for a dozen batches it becomes cheaper than dry.

shafferpilot said:

so split it up into different vials before the first freeze. This whole idea makes perfect sense to me. liquid yeast is expensive, but if you could make it last for a dozen batches it becomes cheaper than dry.

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Maybe not cheaper once you figure in the DME for starters, but close to the same, at least, with much better variety.

Dr Vorlauf said:

Do you sterilize the glycerine?

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No, never have.