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Splitting starter at high krausen

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carpedaym

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I'll be brewing two batches; a full 23L and a 5L test batch (first all grain mash for me). I've got my starter on and have calculated that it should create enough yeast cells for both batches. Both brews are pretty similar - a pale ale and an english bitters - hence using the same starter.

From what I understand, it's best to pitch your starter at high krausen when the yeast are in party-mode. Now that I'm staring at the foamy head on my starter, I'm starting to realise it will be difficult to split in the correct proportions.

Does anyone have any advice on how to ensure I split it evenly? The options I've thought of:
  • Try to distribute the foam evenly* between batches, then pour the starter liquid evenly too
  • Try to stir the krausen into the starter, then pour evenly
  • Postpone my brewing until the krausen is pretty much gone, then pour in
Cheers fellas, I'll appreciate any input.


*when I say "evenly", I really mean correctly distributed between the two different sized starters.
 

philmud

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carpedaym said:
I've got my starter on and have calculated that it should create enough yeast cells for both batches.
I'm not an expert by any stretch. In fact, I've never made a starter, but, when you say your calculations indicate you have enough cells to pitch both batches, how much leeway do you have? Unless you need to be accurate within 50mls or so, I'd eyeball it.

Also, I could be wrong, but is the point of pitching at high krausen not that this is when the yeast are most active, not to actually pitch the krausen per se? I reckon you'll be fine.
 

Ducatiboy stu

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High krausen is the best time to split and pitch or make further starters
 

manticle

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Also, I could be wrong, but is the point of pitching at high krausen not that this is when the yeast are most active, not to actually pitch the krausen per se? I reckon you'll be fine.
What do you mean by this exactly Phil?

Krausen contains very active, healthy yeast so discarding the krausen seems counter-intuitive to me.

However it is worth distinguishing between an active starter and stepped up yeast - if just trying to grow yeast cells you may 'mistreat' the wort (oxygenate, increased temps etc) and therefore you are best off leaving the wort behind. In this case I think it's better to let it ferment out, decant and pitch the slurry only (or put it into fresh wort again and build to high krausen for a second time) so you don't add oxidised, estery beer to your main wort.

I use wort from the same batch (no-chill so I have the time) and always pitch at high krausen but I do not ferment my starters at high temps, nor oxygentate once fermentation has started but I aim to pitch active starters and do not step up from slants etc.
 

carpedaym

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I guess I'll try to distribute the krausen if it is still around tomorrow morning (it was brew-day today). I wasn't sure whether the krausen was made yeast or something else. Thanks for clarifying.

I don't think my starter is too "mistreated" - I gave it intermittent shakes for the first 12 hours, but as I understand it, all that oxygen is eaten by my yeasty friends as they multiply during that time. It's just been at room temperature, which at this time of year is pretty much within the yeast's comfort zone. I'm willing to pitch it, as it will only be 5% of my overall brew volume.

Last time I brewed, I did a similar thing and split a starter, but that time I cold crashed and decanted first. I must not have mixed it up enough, as I found that the last 30mLs or so came out a lot creamier; hence my concerns this time!

Thanks for the help guys.
 

Ducatiboy stu

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Just adding to this, when your fermenter is at high krausen draw out 500ml from the tap. Instant starter. Did this for years
 

philmud

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manticle said:
What do you mean by this exactly Phil?

Krausen contains very active, healthy yeast so discarding the krausen seems counter-intuitive to me.

However it is worth distinguishing between an active starter and stepped up yeast - if just trying to grow yeast cells you may 'mistreat' the wort (oxygenate, increased temps etc) and therefore you are best off leaving the wort behind. In this case I think it's better to let it ferment out, decant and pitch the slurry only (or put it into fresh wort again and build to high krausen for a second time) so you don't add oxidised, estery beer to your main wort.

I use wort from the same batch (no-chill so I have the time) and always pitch at high krausen but I do not ferment my starters at high temps, nor oxygentate once fermentation has started but I aim to pitch active starters and do not step up from slants etc.
I'm not suggesting he discard the krausen, just that the bulk of the yeast cells are in the liquid portion of the starter, and therefore the point of pitching at high krausen is to take advantage of active yeast, as opposed to a greater number of cells due to the presence of krausen. I'm basing that on an assumption though, so happy to be told I'm wrong.
 

manticle

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I'm not following. The krausen contains cells and the starter contains cells. the yeast is mainly all healthy yeast (rather than early floculators) the growth cycle is nearing completion or has completed so your count is maximised so you get the best of all worlds.

The point of an active starter is to pitch healthy yeast and the point of stepping up is to increase yeast cell count yeast - both referred to as starters, both different points and processes. I'm guessing this is what you are referring to?
 

philmud

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I think we are in agreement. OP wants to pitch enough cells for both planned fermentations, and as I understand his original question, he is/was planning to so this at high krausen to ensure he pitched cells that are as healthy as possible. He was concerned that he would not accurately apportion starter and krausen to each wort - my original response suggested that as long as his calculation about having enough cells wasn't borderline, a rough measurement including both starter and krausen shouldn't result in either wort being underpitched.

Again, if that's not the right assumption, I'm happy to defer to those with more experience.
 

carpedaym

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To clarify, I guess I was borderline on cells and that is why I wanted to do a starter - to increase the cell count to something I was more confident with AND pitch when they're most active.
 

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