Yeast Starter

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mtom1991

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I have used liquid yeast and a yeast starter for my last two brews. However i have just dumped the full starter (1L) into the fermentation vessel when pitching.

Looking to separate it off this time and just want to clarify the method:

  • Get WLP940 + Starter Wort up to Temp (13*C ?) should i make the starter at optimum ferm temp ? or at room temp as is the case with Ale yeast ? Iv made my previous starts at 21*C
  • Make Starter
  • Stir Plate @13*C for 48hrs
  • Chill @ ? *C for ? hrs to cold crash yeast
  • Decant Starter Wort + Dispose
  • Get Yeast up to Target Pitch Temp 10-13*C
  • Add small volume of Wort swirl and Pitch
 

Gnomebrewer

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Make starter
Get WLP940 up to room temp
Chill starter to room temp
Pitch WLP940
Ferment at room temp until done. Probably about 48 hours.
Chill at as close to freezing as you can for at least 24 hours, preferably 48 to 72 hours.
Decant excess wort (leave a little bit behind for swirling) on brew day and raise yeast to (or just below) target pitch temp (which is ideally a bit below target ferment temp).
Swirl yeast slurry and pitch.
 
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mtom1991

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How long can the yeast starter be stored in its chilled state ? is there abit of a window to brew in or does the timing need to be pretty strict ?
 

marc1

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How long can the yeast starter be stored in its chilled state ? is there abit of a window to brew in or does the timing need to be pretty strict ?
Easily a few weeks, if it gets out a few months make another starter with it.

You can also make a bigger starter and spilt off some yeast for your next brew. Store it in the fridge under the fermented starter wort. Mason jars work great for this.
 

CaptMogul

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I just made a S05 starter ( over build 3 generation) dated 5-21. Kicked off within 24 hrs
Ed B
 
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mtom1991

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Cue 5 million questions from me:

what size sample would I need to take from my initial starter ?

What size mason jars would be ideal for this for the scale I brew at ? (Currently make 1L starters with 2x WLP packets)

Something like 0.25 L jars ?

Should the air gap be kept to a minimum ? I.e would I just cap the yeast with a small layer of fermented wort or fill to near the top to eliminate air ?

If for example the original yeast I purchase has a use by date 6 months in the future. Would any successive Yeast starters that I split off from the original also need to be used by then ?
 

Gnomebrewer

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Cue 5 million questions from me:

what size sample would I need to take from my initial starter ?
Use a yeast starter calculator like this one Yeast Pitch Rate and Starter Calculator - Brewer's Friend to work out how much yeast you need for your brew, and how much you have in your 'leftover' portion for future brews. The amount you keep doesn't really matter, as long as you know roughly how much yeast you're keeping. FWIW, I keep 500mL if I have an empty 500mL jar, or 900mL if I have a spare 900mL jar.

What size mason jars would be ideal for this for the scale I brew at ? (Currently make 1L starters with 2x WLP packets)

Something like 0.25 L jars ?
I'm not quite sure what you're asking here. Are you making starters in mason jars? Ideally, you'd make starters in a conical/erlenmeyer flask on a stir plate. A flask that can take 1L of wort will cover most ale brewing situations, a bit bigger to overbuild starters, and much bigger if you're doing high gravity ales and/or lagers. Also, using two packs of yeast in a 1L starter isn't very economical or necessary. As you'll see if you play with the calculator, there's not much difference in final cell count if starting with one vs two packs of yeast in a 1L starter. With two packs of WLP yeast, you don't need a starter for most beers unless the yeast is very old.

Should the air gap be kept to a minimum ? I.e would I just cap the yeast with a small layer of fermented wort or fill to near the top to eliminate air ?
Yes, minimise air space for yeast storage.

If for example the original yeast I purchase has a use by date 6 months in the future. Would any successive Yeast starters that I split off from the original also need to be used by then ?
No. The use by date is for the yeast in the packed. When you make a starter, you create new yeast cells with a new lifespan. Yeast starters that we make aren't as good quality as the stuff out of Whitelabs though, so viability will drop faster than it does with fresh yeast.
 
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mtom1991

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I'm not quite sure what you're asking here. Are you making starters in mason jars? Ideally, you'd make starters in a conical/erlenmeyer flask on a stir
I use a 2L Conical flask for making up starters.

what I’m asking is what size jars should I look to purchase for storing the split off yeast samples in, what would be adequate ?
 

Gnomebrewer

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Some 250mL and 500mL would work. For example, using the calculator I linked above, I you're making 5.5 gallons of 1.050 ale, you need around 193 billion cells. Say you have a pack of WLP yeast with an estimated 70 billion cells, a 2L starter on a stir plate will give you about 338 billion cells, so you could comfortably take off 500mL (a quarter of the starter so around 85 billion cells) to use in your next starter. It actually doesn't make a big difference how old your yeast pack is (providing it's not expired) for 2L starters, even with 10% viability (10 billion cells) to start with, a 2L stir plate starter finishes with 278 billion cells (not much different to the 338 billion with the 70 billion cell pack of yeast). 250mL jars will come in handy if you need to make a starter for a bigger beer. 5.5 gallons of 1.080 ale needs about 300 billion cells, so it doesn't leave much out of your 2L starter.
 
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