Harvested yeast - how much do I have???

[jjinsa]

So I harvested my first bit of yeast to keep for my next batch.

I absolutely cannot find any information to be able to CONFIDENTLY tell how much yeast I have in my jar, as every site and post confused me.

I harvested the slurry from a 3.8L batch (1 gallon) and poured it into a 360ml jar. I washed it 2-3 times with sterilized water.

I now have this (see pictures). The first picture was after washing a few times and leaving in fridge for a day or 2, and after I picked it up a white later formed on top of the slurry part - pic 2.

The total slurry part is 180ml and there is about 180ml water on top.

How much yeast do I have?

View attachment ImageUploadedByHome Brew1454848966.678945.jpgView attachment ImageUploadedByHome Brew1454848989.518456.jpg

 

[JohnnyBrewGood]

I would say you have half a jar.

 

[jjinsa]

I would say you have half a jar.

Please share the calculation you used to get that...

 

[JohnnyBrewGood]

Umm.... I used your photo.

I use http://www.mrmalty.com/calc/calc.html

Click on repitching slurry.

I have learned I need about one cup of slurry for 5 gallons so I use that. .75 a cup actually so I round up a bit.

 

[jjinsa]

Umm.... I used your photo.



I use http://www.mrmalty.com/calc/calc.html



Click on repitching slurry.



I have learned I need about one cup of slurry for 5 gallons so I use that. .75 a cup actually so I round up a bit.

The thing that confuses me .... What is 1 cup of slurry? Is it just the lower half of what is in my picture (ie yeast), or is it all of that mixed together with the water? Difficult to find a definition

 

[Jwin]

A cup of slurry conpacted and stored over a few weeks is probably as viable as a fresh uncompacted cup

But to answer, just the yeast and enough water to stir it up.

 

[jjinsa]

A cup of slurry conpacted and stored over a few weeks is probably as viable as a fresh uncompacted cup

But to answer, just the yeast and enough water to stir it up.

So to help me understand... In my pictures, if that jar was exactly 1 cup in volume, I would have half a cup of slurry??

Basically, in the picture, there is 180ml of water and 180ml of "slurry" in the bottom half... so when I use calculators where they tell you to pitch "x" amount of slurry, is it referring to only what is in the bottom half of the jar (as in my picture), or the whole jar all mixed together?

 

[flars]

So to help me understand... In my pictures, if that jar was exactly 1 cup in volume, I would have half a cup of slurry??

Yes, you would have one-half cup of slurry.

This stickie may help understand what is going on and how to calculate how many yeast cells were harvested. Don't try to read the entire thread. Only need to read the OP's post.
https://www.homebrewtalk.com/showthread.php?t=519995

 

[jjinsa]

Thank you flars... that small piece of info is very difficult to pin point (difficult as it is to believe)

 

[flars]

Thank you flars... that small piece of info is very difficult to pin point (difficult as it is to believe)

Not difficult to believe. There are a lot of opinions on the internet. Some are helpful and a lot are not. You will find some very interesting reading here.
https://www.homebrewersassociation.org/forum/index.php?board=193.0

 

[JohnnyBrewGood]

Yes, you would have one-half cup of slurry.

Although this is true, it is not necessarily the truest statement.

"slurry" As I understand it is yeast in water/beer. how thick the slurry is, or how many yeast cells are suspended is the question.

Slurry is slurry. yeast in a liquid.

A billion cells in a gallon of liquid or a billion in a cup of liquid, both slurry, both a billion cells.

That's why Mr Maly asks is it thick or thin?

 

[JohnnyBrewGood]

there are a lot of opinions on the internet. ]

this

 

[jjinsa]

What I want to know is - in my picture, is the slurry everything in the jar, or the stuff that has settled into the bottom half?

So that is a 360ml jar - do I have 360ml slurry, or 180ml slurry (and 180ml water)?

 

[flars]

What I want to know is - in my picture, is the slurry everything in the jar, or the stuff that has settled into the bottom half?

So that is a 360ml jar - do I have 360ml slurry, or 180ml slurry (and 180ml water)?

You have 180 ml of thick slurry. In my opinion slurry is yeast and other materials which drop to the bottom of the fermentor. You would have pure yeast if you could remove the break material and hop debris and anything else that is not yeast.

 

[JohnnyBrewGood]

I do not know how to simplify answer the same question you keep asking.

Try this http://www.mrmalty.com/calc/repitch.html

I disagree (somewhat) with Flars. The jar on the right is more of a "cake" very dense. I wouldn't call it a slurry. If you removed all the liquid, would it flow?

When you washed it and poured it in, was probably a thin slurry.

I would (me, with my experience, what I have read, my understanding of the reading) say......if you decant noneof the liquid you would have a thin slurry, if you decant ALL of the liquid you would have a very thick un-pourable slurry/sludge.
my "slurry" would be in the middle. so about half or the top liquid.
so 2/3 of your container is slurry in my opinion.

 

[jjinsa]

I do not know how to simplify answer the same question you keep asking.

Try this http://www.mrmalty.com/calc/repitch.html

I disagree (somewhat) with Flars. The jar on the right is more of a "cake" very dense. I wouldn't call it a slurry. If you removed all the liquid, would it flow?

When you washed it and poured it in, was probably a thin slurry.

I would (me, with my experience, what I have read, my understanding of the reading) say......if you decant noneof the liquid you would have a thin slurry, if you decant ALL of the liquid you would have a very thick un-pourable slurry/sludge.
my "slurry" would be in the middle. so about half or the top liquid.
so 2/3 of your container is slurry in my opinion.

So as per the Mr Malty sliding scale, if my jar is 50% yeast slurry and 50% water (as in picture) and I mixed the 2 together, you would have it at about 1-1.5 billion cells per ml, and if I poured the water out, it would be closer to 3-4 billion cells per ml (is this what you are saying?)

What would you suggest I use the cell count as if I poured all the water out and only used the lower half?

Quote from Mr Malty:
"This setting allows you to adjust for how thick a slurry you're measuring. If you've ever seen the yeast packed hard into the bottom of a White Labs vial, that is Thick Yeast at 4.5 billion cells per ml. When you harvest a yeast slurry and it has settled for a few hours, that is a thin slurry. Usually, most homebrewers will let their yeast settle for a few days in the fridge between one batch and the next. When you do, you'll notice the yeast has settled a bit and is sort of jelly-like. That is the default setting on the calculator. You'll need to estimate from there for other yeast thickness, but what is most important is keeping track of what you pitched and the results you get from the beer. If you need to adjust up or down, that is OK, just keep track of how you do things each time"

It seems that Mr Malty is saying the bottom half of my Jar would be "thin slurry" even of the water was poured off and you only used the bottom part...

Thoughts?