Storing Yeast In The Freezer

[rich1985]

Hi All,

So I have a liquid wheat beer yeast that goes off in a week but I'll not be brewing till the 20th of December. I was just wondering whether there is anyway of storing it in the freezer. I've read somewhere that I need glycerol (which I don't have). Can I get away with making a starter, pouring a way the wort and putting the slurry in an old glass dolmio jar in the freezer?

Thanks in advance,


Richard

 

[Bigcol49]

Hi!
I think the problem you'll face is a reduction in viable cells. Online, I've seen tables showing the rate of reduction of cells as yeast gets older.
Make a starter, pour off most of the wort when it's finished and use the remaining yeast to make a bigger starter; store this in the fridge until you need it.
As brewday approaches, make a another bigger starter from the one in the fridge so that it's ready for brewday.

 

[MyQul]

Do what BigCol says. If you store yeast in the freezer (without glycol) the ice crystals that form in the cells burst the cells and kill the yeast

 

[foxbat]

+1 to @MyQul. Don't freeze without glycerol because the ice will kill the yeast.

Glycerol is available from Boots under the Glycerin name. £1.49 for 200ml.

 

[rich1985]

Hi!
I think the problem you'll face is a reduction in viable cells. Online, I've seen tables showing the rate of reduction of cells as yeast gets older.
Make a starter, pour off most of the wort when it's finished and use the remaining yeast to make a bigger starter; store this in the fridge until you need it.
As brewday approaches, make a another bigger starter from the one in the fridge so that it's ready for brewday.

So if I make it this week, store it in the fridge and make another starter in December then I should be ok?

 

[Bigcol49]

So if I make it this week, store it in the fridge and make another starter in December then I should be ok?

Hi!
Yes, that's only a little over 3 weeks, so you'll be OK.
Remember that everything must be sanitised really well and keep the yeast covered in the fridge.

 

[Zephyr259]

Do you have a stir plate? If so then a 500 ml starter should bring 6 month old yeast back to around the starting 100 billion cells. You could pitch it into a litre but then you start getting to quite a low pitch rate and the yeast might struggle a bit more. I'd pitch from the second starter unless you want to overbuild and keep some yeast for next time, it'll keep in the fridge for a few months then can be built up again.