First Attempt At Splitting Yeast Slurry

[Truman42]

i had my first go at using the trub from my last batch to save the yeast slurry.

I rinsed it a couple of times then split it into 3 sample jars before tipping the rest into a starter which is on the stir plate now.

However Im not sure if I have enough yeast in each sample jar to create starters when required. Should I perhaps be combining all 3 into 1 jar instead. Trying to get an idea here of how much is generally required to make a decent 1 litre starter. The yeast is US05.

Here is the pic of the sample jars.

 

[Muscovy_333]

i had my first go at using the trub from my last batch to save the yeast slurry.

I rinsed it a couple of times then split it into 3 sample jars before tipping the rest into a starter which is on the stir plate now.

However Im not sure if I have enough yeast in each sample jar to create starters when required. Should I perhaps be combining all 3 into 1 jar instead. Trying to get an idea here of how much is generally required to make a decent 1 litre starter. The yeast is US05.

Here is the pic of the sample jars.

View attachment 52326

Not that i'm the resident expert Truman, but i generally aim for about 10 mm in the bottom of a corona bottle once it has settled out. I rinse until the liquid above is clear also.
Sometimes i get up to 20 mm of clean milky coloured yeast settle out in which case i would agitate by shaking it up, pour half into my starter and re-cap the remaining to store in the fridge for another 6 months if needs be.


Looking at what you have i would combine them this time around IMHO.

 

[Truman42]

Ok then, well I will combine all of this into one and rinse again until I get it clearer.

I put a fair bit more than these three into my starter and it has a nice layer of krausen after 10 hours on the stir plate.

 

[Muscovy_333]

Success!
I'm certainly not the expert, just do what i do cause it works for me.
If you have Krausen you are on your way.

Others have mentioned that they do not even bother rinsing their yeast, just dump a bit of yeast cake straight into starter with no problems.
The problem being that you can not really gauge how much is viable yeast.
At least when you rinse you get a good idea of how much yeast you have collected.
my 2c, others will no doubt have differeing opinions

Just go with what works for you + some logic.

 

[flano]

I am probably the least knowledgable about this but all I do is this.
tip the left over dreg/sediment from fermenter into a sterile jug...usually 1 litre.
Then split it into 2 dif containers. 2 x 500 mls yeast .
put it in the fridge.
when it is time to use it I just tip off the clear stuff off one 500 mil batch and pour the yeast into wort.
I don't bother letting it get to room temp...makes no difference from I can tell...if anything it gets going quicker when it comes straight our of the fridge.

works for me.
another thing I think is the faster it gets going the clearer the finished product seems to be.
The beer sI do with yeast this way are always clearer than when I add the pakcet of dry yeast it seems.

I could be totally wrong but this is just my perception of it all.

 

[stux]

FWIW, which is not much

When I split wyeast packs four ways I end up with 15-20ml of dense yeast slurry in a 30ml sample jar, and once they get old, they require quite a bit of building up

Not really sure of the scale on your picture, so not sure how big your sample jars are.

 

[Truman42]

Thanks for the tips guys...After 1.5 days the krausen seems to have slowed right down.
I dont think I pitched enough yeast in this one and if I were going to use this starter to pitch. (Just experementing at this stage) Im guessing this is where I might need to step it up from 800mls to 1 litre and see how it goes.

Just a question, how long do you guys run your stir plates for? Ive been turning mine on in the morning and off again at night.

 

[Muscovy_333]

Thanks for the tips guys...After 1.5 days the krausen seems to have slowed right down.
I dont think I pitched enough yeast in this one and if I were going to use this starter to pitch. (Just experementing at this stage) Im guessing this is where I might need to step it up from 800mls to 1 litre and see how it goes.

Just a question, how long do you guys run your stir plates for? Ive been turning mine on in the morning and off again at night.

I dont use a stir plate, but i do make sure i have a constant temperature so the yeast do not fall asleep.
Yeasties grow exponentially (cell division) and need constant temps to make sure this happens effectively, when they are happy teh exponential growth slows and they start working on converting maltose to alcohol.

IMHO the name of the game is constant and un-interupted growth conditions, temp fluctuations are not their friend.

I normally get my starter going the day before (2-4litres) and once a Krausen is happening pitch it.

Probably not perfect but a vast improvement on sprinkling dried yeast on top.

Their are a few claculators to figure out your cell count available but i'm not their yet.

 

[Truman42]

I dont use a stir plate, but i do make sure i have a constant temperature so the yeast do not fall asleep.
Yeasties grow exponentially (cell division) and need constant temps to make sure this happens effectively, when they are happy teh exponential growth slows and they start working on converting maltose to alcohol.

IMHO the name of the game is constant and un-interupted growth conditions, temp fluctuations are not their friend.

I normally get my starter going the day before (2-4litres) and once a Krausen is happening pitch it.

Probably not perfect but a vast improvement on sprinkling dried yeast on top.

Their are a few claculators to figure out your cell count available but i'm not their yet.

Out of interest how many litres are you pitching your 2-4 litre starter into? I think for my batches of 18-20 litres a 1 litre starter should be enough from what Ive read.

 

[stux]

I run my stirplate 24/7

I use http://www.yeastcalc.com to work out my steps

I'll generally do a step for 24-36 hrs. I figure I get max growth that way.

I add the full step flash to the next steps wort. At the end I chill and decant off the spent wort and then only pitch slurry

Works for me

 

[Muscovy_333]

Out of interest how many litres are you pitching your 2-4 litre starter into? I think for my batches of 18-20 litres a 1 litre starter should be enough from what Ive read.

23 litre batches
I like to over engineer when im not calculating specifically


Cell counts are on my list of too do.

 

[Muscovy_333]

I run my stirplate 24/7

I use http://www.yeastcalc.com to work out my steps

I'll generally do a step for 24-36 hrs. I figure I get max growth that way.

I add the full step flash to the next steps wort. At the end I chill and decant off the spent wort and then only pitch slurry

Works for me

Not shure how to read that plot...and i call myself a scientist!

I will need to spend some time on that tonight.

 

[Truman42]

I run my stirplate 24/7

I use http://www.yeastcalc.com to work out my steps

I'll generally do a step for 24-36 hrs. I figure I get max growth that way.

I add the full step flash to the next steps wort. At the end I chill and decant off the spent wort and then only pitch slurry

Works for me

Thanks Stux, that calculator will come in handy. So in the screen shot below Ive done a scenario where I use 25% of a Wyeast smack pack (Split the rest into vials for later use) and have stepped it up each time to get to my final count.



However the calc says 50-100million cells/ml is the optimal range for maximizing cell growth, which would make my step ups more like this shot below.

Is this what you generally do? Im stepping up to 1.4 litres when all I really need is 1 litre.

 

[JoeF]

My understanding is that if you start with say 1.5 ltrs, your next step is 1.5 ltrs aswell...not 3 ltrs in total.

I split my packs into thirds so eneter 33.3% and the production date of the yeast to determine viability.

I 'think' that's correct - can someone confirm?

 

[Steve@PMF82]

My understanding is that if you start with say 1.5 ltrs, your next step is 1.5 ltrs aswell...not 3 ltrs in total.

I split my packs into thirds so eneter 33.3% and the production date of the yeast to determine viability.

I 'think' that's correct - can someone confirm?

View attachment 52382

You would be better off having that first step smaller @ 500ml, let it finish and clear, decant spent wort then next step of 2L.
Your initial innoculation rate is too low (17mil/ml), you may stress the yeast, it is not optimal conditions for growth.

 

[Steve@PMF82]

Thanks Stux, that calculator will come in handy. So in the screen shot below Ive done a scenario where I use 25% of a Wyeast smack pack (Split the rest into vials for later use) and have stepped it up each time to get to my final count.

View attachment 52348

However the calc says 50-100million cells/ml is the optimal range for maximizing cell growth, which would make my step ups more like this shot below.

Is this what you generally do? Im stepping up to 1.4 litres when all I really need is 1 litre.

View attachment 52349

Just make your final step only 1L and your problem is solved, it wont matter if your inoculation rate does not match the previous steps. As long as your somewhere in that range of 50 - 100mil/ml it will be fine.

You can always do the 1.4L starter anyway and keep some of the yeast for use in your nect batch's starter.

 

[JoeF]

You would be better off having that first step smaller @ 500ml, let it finish and clear, decant spent wort then next step of 2L.
Your initial innoculation rate is too low (17mil/ml), you may stress the yeast, it is not optimal conditions for growth.

Ahaaaa.

Thank you Beer4U.

That makes sense. Still new at the liquid yeast thing.
The only problem is i've already pitch 1/3 of a pack last night into 1.5 ltrs in my Erlenmyer flask.
Ooops. Any hints on what I should do?

Thanks again

 

[Truman42]

Just make your final step only 1L and your problem is solved, it wont matter if your inoculation rate does not match the previous steps. As long as your somewhere in that range of 50 - 100mil/ml it will be fine.

You can always do the 1.4L starter anyway and keep some of the yeast for use in your nect batch's starter.

If I make my final step 1 litre it bumps up the innoculation rate over the range of 50-100mil/ml to 132mil/ml as sen in the shot below. Is that oka for the last step to do this?

 

[Steve@PMF82]

If I make my final step 1 litre it bumps up the innoculation rate over the range of 50-100mil/ml to 132mil/ml as sen in the shot below. Is that oka for the last step to do this?

View attachment 52385

Assuming your yeast sample is 97% viable and you have something near your 25bil starting cell count.
You could just go straight into 400ml then step to 1.4L which will give you 220bil cells, which is close enough to your target for ME, all the while keeping you in the magical 50 - 100mil cells / ml range.

In relation to your question imo it would be fine having that final step at 132 mil/ml innoc rate.
For my money its more important in the earlier steps getting the numbers right, especially if your working with old and / or small samples of yeast, you want the ideal conditions for the yeast to multiply and be healthy which will lessen the chances of something else taking hold.

 

[cdbrown]

I didn't pay any attention to the magical 50-100 innoculation rate - didn't know about it. I pitched a Nov11 czech pilsner into a 1.5L starter. Innoculation rate a measily 17million. It was only through this thread that I noticed that hovering over the cell provided the 50-100 information.

Strange that the optimum pitching rate is around 17 mill cells/ml, but for starters it's 50-100.