Help with how much slurry to use (lager) 34/70

[Panderson1]

For some reason i thought i had a few packs of 34/70 in my fridge. My dumb ass just brewed a 6 gallon Marzen for October.

Anyways i was freaking out but remembered i brewed a Helles 2.5 weeks ago using 34/70.

So i plan on kegging the Helles in a few hours and use whatever slurry is at the bottom immediately after kegging?

It's been a long time since I pitched slurry. I was thinking of gathering around a cup full and pitch that directly?

Any advice?

 

[bellhp]

If you want to refrigerate some for another batch I would save half and pitch half ... If not you can use it all ... won't hurt .

 

[bellhp]

I've got a Vienna Lager brewing now that is repitched yeast from My Marzen I brewed in March (I also used 34/70) ... still have two pint jars in fridge for next two batches.

 

[IslandLizard]

The amount of slurry to reuse from a previous fermentation depends on how much trub it contains.
Sadly, Mr. Malty (one of our favorite yeast (re)pitch calculators) has stopped working with the demise of Flash Player...
So we need to use some sense and estimate.

Yeast typically multiplies her pitched colony 4-5 times during a fermentation. So repitching 1/5 to 1/4 of the complete (previous) yeast cake (trub and all) is probably enough in a batch of similar volume and gravity.

If the gravity of the new batch is a bit higher, use somewhat more.

 

[Panderson1]

The amount of slurry to reuse from a previous fermentation depends on how much trub it contains.
Sadly, Mr. Malty (one of our favorite yeast (re)pitch calculators) has stopped working with the demise of Flash Player...
So we need to use some sense and estimate.

Yeast typically multiplies her pitched colony 4-5 times during a fermentation. So repitching 1/5 to 1/4 of the complete (previous) yeast cake (trub and all) is probably enough in a batch of similar volume and gravity.

If the gravity of the new batch is a bit higher, use somewhat more.

Thanks for the in-depth reply. I'm thinking 1/4 just to be safe.

Edit: and i remember mr malty back in the days! Great little tool

 

[hottpeper13]

If you use Brew dad's yeast starter calculator add a second step at 20 liters and off the stir plate and it will tell you the cell count of that cake and then split it up by dividing the number of cells to pitch into the amount of the cake. Most of the lagers i do need 1/2 cake, Ales-1/4 and German ales 1/3.

 

[Bassman2003]

Warm or cold fermented lager? If cold, I would go with 1/2 of what you can pour out of the fermenter.

 

[Miraculix]

Just throw your wort on top in the same fermenter.

 

[FloppyKnockers]

^^ This. I'll save the cake in two jars if not using right away. However, on the rare times that I need to pitch right after I keg, I'll just transfer the new wort right into the bucket I just kegged from.

I've only ever done this with 34/70 and worked like a champ every time.