Freezing whitelabs vials

I've got a vial of whitelabs German lager yeast that's got a best before of 26th of June. I just don't have the time to use it before the end of the month so i was wondering if it would be possible just to pop it in the freezer until i get round to using it.

Cheers
B

[graysalchemy]

Freezing isn't the best method of storage but it does work.Ihowever you need to freeze it with gycerin 50% yeast 25% water 25% glcerin. If you don't the yeast cells will fracture and viabilty will drop dramatically.Plenty on line about it.

Keep it in the Fridge and 24/36hrs before you are going to use it and make a 1 litre Starter with it. I have done this with 3 month out of date vials without a problem.

I've got a starter on the go right now from a Whitelabs Kölsch yeast that's out of date at the end of May. Got a 4L starter bubbling away in a demijohn.

It's not perfect to use out of date yeast, but it will certainly still do the job with a bit of help.

Brycey, Ive got a fair bit of experience with freezing yeasts as I wanted to be able to brew whatever I wanted but maintain plenty of viable yeast on hand.

graysalchemy is on the money with the using glycerine before freezing. However I would use it at 25%. Glycerine is 1.26g per ml which I find a far easier method of measuring it out. In your case I would split the vial between 2 or 3 vials use a 25% glycerine (say 50ml yeast + 12.5ml (15.75g) glycerine. Now with freezing you want to get it as close as possible to storage temperature really fast. best way to do this is via an Ice bath with some salt. Then into the freezer. This prevents the cells from slow freezing which creates those shard like ice characteristics which burst the cell wall.

The key to reviving the yeast is as follows:
1. Remove from freezer to fridge, then from fridge to room temp. There is no rush take your time.
2. Pitch the yeast into a 100ml starter of 1.020 wort, this lets the yeast wake up and begin to do its thing.
3. After a few days pitch this onto a stir plate in a 500ml 1040 starter for 24 hours.
4. Then pitch onto a 1.5L 1040 starter for 24 hours. At the end of this step you should have a sufficient amount of yeast cells to pitch into a batch.

Be wary yeast freezing becomes a hobby of its own.

Cheers!

Don't forget as this is a lager yeast you'll need 3 times normal amount if fermenting at the normal lager temp (9 to 12c ) so once you're ready to use you'll need to make the starter as above then step it up to a larger starter .

If you will be using it in the next few months then just keep it in the fridge but step up a starter a few days before brewing.

graysalchemy is on the money with the using glycerine before freezing. However I would use it at 25%. Glycerine is 1.26g per ml which I find a far easier method of measuring it out. In your case I would split the vial between 2 or 3 vials use a 25% glycerine (say 50ml yeast + 12.5ml (15.75g) glycerine. Now with freezing you want to get it as close as possible to storage temperature really fast. best way to do this is via an Ice bath with some salt. Then into the freezer. This prevents the cells from slow freezing which creates those shard like ice characteristics which burst the cell wall.

So, 25% of the slurry volume as glycerine and no additional water then?

Cheers guy's
I think I'll just leave it in the fridge! Hopefully I'll manage to get it used mid to late July. I'll start it off then step it up to a 4 or 5 litre starter

B

I don't use Whitelabs but regularly resurrect Wyeast smack packs up to 18 months old, as long as they have been kept in a fridge.