Author Topic: Building up a starter  (Read 1031 times)

Offline qm3k

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Building up a starter
« on: September 20, 2016, 06:42:53 PM »
Hi all,

I typically make starters every time I brew, but I've never actually had to step one up.

I am planning to brew a Czech Pilsner, and the yeast I was able to get is a bit old (March 2016, only 19.63% viable according to BeerSmith).

Also according to BeerSmith, I need 467.7 billion cells, so I have a long way to go.

As I'm playing with the starter calculator in the program, it LOOKS like I can make a 1L starter on a stir plate to get the cell count up to 117 billion, so a bit more than a new package of yeast.

My question is, then, do I simply go ahead and pitch the new, happy yeast into another starter as though I'm pitching a fresh package of yeast (another 2.69L on a stir plate gets me pretty close to the recommended pitch rate of 467.7 billion according to the software)?

It seems simple enough, but I just want to make sure I'm not missing something important.

Thanks.

Offline mainebrewer

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Re: Building up a starter
« Reply #1 on: September 20, 2016, 09:00:13 PM »
That's pretty much all there is to it.
Some are going the "shaken not stirred" route. There's a lot of stuff on this forum on that.
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Offline flars

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Re: Building up a starter
« Reply #2 on: September 20, 2016, 09:15:34 PM »
Hi all,

I typically make starters every time I brew, but I've never actually had to step one up.

I am planning to brew a Czech Pilsner, and the yeast I was able to get is a bit old (March 2016, only 19.63% viable according to BeerSmith).

Also according to BeerSmith, I need 467.7 billion cells, so I have a long way to go.

As I'm playing with the starter calculator in the program, it LOOKS like I can make a 1L starter on a stir plate to get the cell count up to 117 billion, so a bit more than a new package of yeast.

My question is, then, do I simply go ahead and pitch the new, happy yeast into another starter as though I'm pitching a fresh package of yeast (another 2.69L on a stir plate gets me pretty close to the recommended pitch rate of 467.7 billion according to the software)?

It seems simple enough, but I just want to make sure I'm not missing something important.

Thanks.
You would decant the spent starter wort off the propagated yeast before adding new wort for the step up to reduce the total volume in your flask.  I find this calculator very easy to use.
http://www.brewunited.com/yeast_calculator.php

Offline Saccharomyces

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Re: Building up a starter
« Reply #3 on: September 21, 2016, 12:32:33 AM »
You do not want to let a starter ferment out.  You want to step it high krausen.  You also want to pitch at high krausen.  The maximum cell density for a liter is 200 billion cells.  The amount of cells that one can grow is based on the volume of the starter, initial dissolved O2, and the amount of available carbon.  Sugar is carbon bound to water, which is why it is a carbohydrate.

By the way, "Shaken, not Stirred" is a technique that I had been using for over two decades when I introduced it to this forum and couple of others.

Offline HoosierBrew

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Re: Building up a starter
« Reply #4 on: September 21, 2016, 12:34:34 AM »
Good too see you post, Sacch!
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Offline tommymorris

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Re: Building up a starter
« Reply #5 on: September 21, 2016, 01:05:47 AM »
You do not want to let a starter ferment out.  You want to step it high krausen.  You also want to pitch at high krausen.  The maximum cell density for a liter is 200 billion cells.  The amount of cells that one can grow is based on the volume of the starter, initial dissolved O2, and the amount of available carbon.  Sugar is carbon bound to water, which is why it is a carbohydrate.

By the way, "Shaken, not Stirred" is a technique that I had been using for over two decades when I introduced it to this forum and couple of others.
I switched to "Shaken, not Stirred" a few months ago. I am really happy with the results. Easy and effective. Thanks, Mark.

Offline jeffjm

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Re: Building up a starter
« Reply #6 on: September 22, 2016, 11:42:53 AM »
Like others, I've been trying SNS lately and been happy with it. I have a couple questions - apologies if they've been answered elsewhere but I didn't find them when I searched.

First - since the saturation point is about 200 billion cells/liter, and since we're counting on the yeast doubling - does that mean that a one liter SNS starter is suitable for any pitch where we calculate we need no more than 400 billion cells?

And second - if I'm making a strong lager, where I might want 500 million or more cells, how would I step the SNS starter up to 2L? We want to step at high krausen, not decant, so would I need an eight-liter or larger vessel in order to maintain the headspace ratio?

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Offline ynotbrusum

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Re: Building up a starter
« Reply #7 on: September 22, 2016, 09:37:10 PM »
For stepping up on lagers, I occasionally have also just made small batches of beer - I hate to waste what otherwise might be decent wort for, say, a helles or similar light lager.  But under Mark's approach, you retain the "spent" wort, because it is at high krausen and then pitch directly into and get that new "starter" up to high krausen for pitching into the full size batch (if I understand the approach correctly).  For what it is worth, I think at high krausen, the starter can handle fermenting a lot larger batch than you might otherwise expect based on calculators for recipes - lager or ale.

After the pitch and ferment, you can re-use the yeast cake directly, if you time your beer making for that purpose.
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