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Reculturing Coopers Yeast - Stepped starter?

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Keano16

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Hi all, I'm after some advice on reculturing coppers yeast. I'm about to do a Coopers Pale clone and have made a 1ltr starter using degs from 6 bottles of pale. Starter has been spinning away on stir plate for 36 hours and looks healthy. My question is whether I would need to step up the starter for a 27ltr batch or should that be enough yeast. Cheers
 

kadmium

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Absolutely you should step it up. I do a 1.5L starter from packets, which start with a known 100B cells. I would do another 1.5L step
 

kadmium

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Hey, so I was on mobile and I figure I should probably expand on why you should step it up.

Using pure, ready to go liquid yeast packets you get 100B (Billion) cells per packet, with a weight of around 120g. A _very_ rough estimate is 1B cells per Gram of liquid (There are about 4.5 billion yeast cells in 1 milliliter of yeast solids (solids with no excess liquid). in a slurry, only about 25% of the mass is yeast solids.)

Dry yeast is around 20B/g

So, say you managed to get 6 bottles, and from each of those managed to harvest around 3g of yeast, for a total of 18g of yeast. That's 1.8B cells. That is around 1/100th of what you need for a healthy pitch. That IF 100% of those cells are healthy. And that's IF you managed to get 18g of yeast, who knows? So, lets assume after sitting in bottles for so long, etc etc you have 50% viability. This means, .9B cells to start.

Using an online calculator and information from Brewdad, you want to inoculate at between 20-100 million per ml of liquid. The pitch rate from your harvest is around 1.3m / ml

The growth rate for pitch rates that low are no more than 1.4 billion cells per gram of extract with a total extract weight of 100g for 1 L. This means you should end up with around 140B cells with a growth rate of 70 (this is all VERY loose calculations) so, a second 1L step would then equate to 140m/ml inoculation for a total of 282B cells and a decent pitch rate.

Bear in mind, there is a LOT of guess work there. However, I would step it up by crashing it, then doing another 1L of starter liquid and pitching the slurry. Then you KNOW you have enough Yeast.
 

JDW81

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The general advice when recapturing from any bottle is to step up your starters slowly and don’t put it straight into a large (i.e. 1L starter). There’s generally not enough viable yeast in each bottle (even 6) to be able to handle a starter that big.

All the reading I’ve done (and my own practice when I recapture from bottles - which isn’t that often any more) suggests start with a small volume starter (i.e. 100-200mL), let ferment for ~48 hours then step up to 500mL, then step up again to 1.5-2L after another 48 hours. That way you’re pitching an appropriate amount of yeast into an appropriately sized starter.

This is pretty much how the big yeast guys do it as well (When culturing from small volumes). They start with a very small/pure colony on a plate, theN slowly step up the size until they can make commercial quantities of it.

JD
 

kadmium

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The general advice when recapturing from any bottle is to step up your starters slowly and don’t put it straight into a large (i.e. 1L starter). There’s generally not enough viable yeast in each bottle (even 6) to be able to handle a starter that big.

All the reading I’ve done (and my own practice when I recapture from bottles - which isn’t that often any more) suggests start with a small volume starter (i.e. 100-200mL), let ferment for ~48 hours then step up to 500mL, then step up again to 1.5-2L after another 48 hours. That way you’re pitching an appropriate amount of yeast into an appropriately sized starter.

This is pretty much how the big yeast guys do it as well (When culturing from small volumes). They start with a very small/pure colony on a plate, theN slowly step up the size until they can make commercial quantities of it.

JD
Agreed, however I was addressing the fact he's already done it! It shouldn't be too bad, and a growth factor of 70+ is huge but should be ok.

100% though best practice is as you described.
 

Keano16

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Thanks for the feedback, looks like another starter is the consensus then
 

Vic

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Hi all, I'm after some advice on reculturing coppers yeast. I'm about to do a Coopers Pale clone and have made a 1ltr starter using degs from 6 bottles of pale. Starter has been spinning away on stir plate for 36 hours and looks healthy. My question is whether I would need to step up the starter for a 27ltr batch or should that be enough yeast. Cheers
Have a look at the video on the Coopers website.
This uses 6 bottles for a 600ml starter for a 23L batch. A 1L starter on a stir plate should give you enough. I use a 3.6L starter made from 6 bottles for a 42L batch and always get the correct attenuation and an ale indistinguishable from Coopers Original PA. Coopers commercial yeast ferments very vigorously, you need a lot of head space in your fermenter.
 

Paddy Melon

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Thanks for the feedback, looks like another starter is the consensus then
I wish I had asked that question when I first tried it, however I made a 2litre starter 1.040 SG and fortunately it worked and made a great Coopers Pale Ale Clone. I have since been using harvested yeast from the first batch and again it has been working great. Had I asked the question, as you did, I would have done at least a step up or maybe two and saved some yeast from that batch for my next brew. It's all in the learning, and the process is great.
I'm sure you will be happy with the results, I was.
PM.
 

Keano16

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Quick update I stepped up another 1ltr starter. Glad I did as fermentation kicked off quickly and is at FG after only 5 days. Aroma and taste is spot on for a CPA clone. Thanks again for the quick advice.
 

Vic

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Quick update I stepped up another 1ltr starter. Glad I did as fermentation kicked off quickly and is at FG after only 5 days. Aroma and taste is spot on for a CPA clone. Thanks again for the quick advice.
Probably no need for the step up. My current batch started at 1043 and finished at 1006 for 4.7%, a bit above the target of 4.5%. Culture made from 8 CPA stubbies dregs in a 4L starter decanted for a 52.5L batch. I am almost sure this yeast could ferment iron ore!
 
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