Reuse Yeast

[Benfleet Brewery]

I’ve just kegged a (pseudo) German lager using MJ54 Californian Lager Yeast and am planning to brew another Lager tomorrow to finish off my Pilsner Malt. I’ve never reused yeast before but thought I might try it. The yeast cake is currently still sitting in the FV and I do have another FV to use. I was thinking I’d leave it where it is and take a couple of teaspoons out tomorrow to use? Would be grateful for advice please.

 

[Oneflewover]

I’ve just kegged a (pseudo) German lager using MJ54 Californian Lager Yeast and am planning to brew another Lager tomorrow to finish off my Pilsner Malt. I’ve never reused yeast before but thought I might try it. The yeast cake is currently still sitting in the FV and I do have another FV to use. I was thinking I’d leave it where it is and take a couple of teaspoons out tomorrow to use? Would be grateful for advice please.

Reckon you'll need lots more than couple teaspoons. Does Mr Malty have a guide for amounts when using slurry?

 

[Drunkula]

Does Mr Malty have a guide for amounts when using slurry?

Yup.

 

[Oneflewover]

Yup.

There you are then, consult the esteemed Mr Malty

 

[Michael Burnley]

I've started to keep the slurry in sterilised glass clip lid jars in the fridge. According to brewers friend website slurry has a minimum of 1 billion cells/ml.

If you use the calculator and change yeast type to slurry it will work out how much you need to use

Yeast Pitch Rate and Starter Calculator - Brewer's Friend

 

[Northern_Brewer]

Take the Mr Malty numbers with a bit of a pinch of salt, he tends to be on the generous side in general.

You don't want to be pitching a full cake from a previous fermentation as you want the yeast to be going through some cell divisions during the fermentation. And it depends a bit on whether you're fermenting at lager temperatures or not, in which case you need more cells as they will grow more slowly.

With those caveats, you want more than a few spoonfuls, maybe a small mug/jar-ful?

 

[Benfleet Brewery]

Take the Mr Malty numbers with a bit of a pinch of salt, he tends to be on the generous side in general.

You don't want to be pitching a full cake from a previous fermentation as you want the yeast to be going through some cell divisions during the fermentation. And it depends a bit on whether you're fermenting at lager temperatures or not, in which case you need more cells as they will grow more slowly.

With those caveats, you want more than a few spoonfuls, maybe a small mug/jar-ful?

That‘s very helpful, thank you. So, ok to leave it where it is tonight (closed FV in the shed) and take out a sterilised mug full or so tomorrow when I’m ready to pitch?

 

[Northern_Brewer]

As long as it's somewhere clean, not drying out, and not getting frozen or too warm, it'll be fine.

RDWHAHB

 

[Davvy]

Yes - I would second Northern-brewer's comment on "Clean/not dried out.." etc.
I have done it a few times myself with Crossmyloof pale ale, and Mangrove Jack's M44...but saved a % of the cake into a large sterile jam jar or two, where the cake had been rinsed/washed in a demi-john of sterile / pre boiled/cold water. The cake water mix were then put in the fridge to use later.

If you go onto Youtube you will see a variety of methods for this.

From what I can make out the Australians commonly use the cake straight away from the previous brew.

 

[obscure]

I reused yeast for the first time a couple of months ago, first a batch was a Yorkshire Bitter kegged the Yorkshire bitter and same day took about 250ml of slurry from the fermentor and poured it straight into the next batch (barley wine) worked really well, rapid fermentation this was for a 14L batch of Barley Wine, which is still conditioning so can only say the fermentor sample tasted really good.