Re using yeast slurry questions

[laxation]

Overbuild your starter and collect before pitch - it's the only way :chug:

FYI: this is what I mean

Had a read of this - but what is the guy starting with in the glass jar? Is that just the yeast cake sloshed around a bit or something and poured in?

 

[Parks]

Had a read of this - but what is the guy starting with in the glass jar? Is that just the yeast cake sloshed around a bit or something and poured in?

Using a good yeast calculator, overbuild your starter by 100 billion cells. BrewUnited’s Overbuild Harvest function makes this so incredibly easy, you can even download a spreadsheet version.

BrewUnited's Yeast Starter Calculator

 

[laxation]

Sorry its completely new to me and I don't know where he's getting his starter from... Is it still from reusing slurry?
can you explain like i'm 5?

 

[Parks]

Sorry, it's harvested from a starter which is made from your vial or smack pack of yeast (or potentially from some washed yeast if you wish).

1. Buy a smack pack or Vial
2. Mix 1 to 1.5L of water with 100-150gm dried malt extract (as per what the online calc says)
3. Boil and cool wort to pitching temp.
4. Add yeast and put on stir plate or occasionally mix starter for 12-18hrs
5. Remove 500ML of starter to a sanitised jar, put in the fridge.
6. Pitch remaining liquid into beer or chill and decant.

Then next time do the same process again replacing step 1 with your jar of harvested starter.

(Did that clear it up or make it worse or not address it at all?)

 

[laxation]

Perfect, thank you! So basically you buy the yeast once, but then go nuts repeating steps 2-6?

If I was to do this with Coopers yeast, any idea how many billion yeasts I would have in the dregs of a 6 pack?

 

[TwoCrows]

There is a difference in the meaning of “yeast re-pitch” and a “yeast starter”.

Re-pitching yeast is salvaging /reusing already grown yeast cells that slowed down in there growth and cell divisions. Taking a small amount of the yeast cake / trub from a previous fermentation and introducing them to your new wort.
You need to add enough yeast to start readily and also allowing these cells to grow.

Making a yeast starter is the growing of yeast cells ( starting with low cell numbers , not enough to pitch ) to the desired amount cell numbers required for a known wort batch size.

The size of your wort in Litres and the Original gravity (OG) will require you to calculate the amount of cells required to do the job of successfully arriving at Final gravity (FG).

 

[Parks]

Perfect, thank you! So basically you buy the yeast once, but then go nuts repeating steps 2-6?

Pretty much. I'm up to generation 7 of WY1056 and it's still going strong and seems the same. The only time I ditch them is if I've gone too long and they either don't start or I feel like they may have become infected.

If I was to do this with Coopers yeast, any idea how many billion yeasts I would have in the dregs of a 6 pack?

I haven't done the Coopers thing but I'm sure there's a guide on this forum somewhere...

 

[Parks]

There is a difference in the meaning of “yeast re-pitch” and a “yeast starter”.

The actual meaning of "Yeast Starter" is to literally "start the yeast". It's when you add a small volume of your wort to your yeast and when that is actively fermenting pitch it into your batch.

We tend to use and see the term "Yeast Starter" applied to what is actually "Yeast Propagation". It's the deliberate growth in number of yeast cells.

 

[Lord Raja Goomba I]

Yeast starter = mini wort.

 

[shacked]

From my experience with hefeweizen and wheat beer yeasts (I've tried WLP300, 320 and 351), I've always got really mixed results from repitching from slurry. For example, one repitch of WLP320 ended up being a little bland and quite clear. I've since moved to the build a 'bigger than required' starter model and have had great results.

I've also had this experience with other less (or low) flocculating yeasts like WLP644 (aka "fake brett") but have happily reused slurry from other ale strains: english, american, 'australian', belgians / saison plus a range of lager yeasts.

I'd be interested to understand if this is just me or if there is some factor that is driving this. Could it be that it's only the more flocculant bits/parts of the hefe yeast that end up in the slurry while the balance stays in suspension?

 

[Parks]

Could it be that it's only the more flocculant bits/parts of the hefe yeast that end up in the slurry while the balance stays in suspension?

I would say undoubtedly, yes. You're naturally selecting the more flocculant yeast which will be a big problem if you don't cold crash for a while before removing beer from primary.

 

[koolkuna]

Great post. What size flask do you do you pitch your 1.5 litre H2O/ DME / Yeast mix in ?? I've been looking on the grain and grape site for a purchase. I plan to place my flask on top of my espresso machine and shake every time I walk past. Happy Days