How many yeast cells in a beer?

[Delaney]

Hey!

I'm planning to do a few brews shortly, and I'm thinking of using bottled beer as my inocculant. I'm just wondering how many yeast cells would be in a typical beer? I was impatient and bottled early, so there's a few mm of yeast on the bottom of the bottles I'd be using...

I'll make a starter if need be, just want to avoid work if it's unnecessary.

Cheers,

Delaney.

 

[biodarwin]

Not only will you need to make a starter, but you will need to step it up multiple times. The yeast out of the bottom of a beer has a pretty small cell count and viability. Without a hemocytometer it will be a bit difficult to estimate the cell count.

 

[WoodlandBrew]

Agreed, and without staining the viability is unknown. A typical commercial bottle conditioned beer has 1 million cells per liter. Settled slurry is about 1 billion cells per ml. A few millimeters of yeast would probably be about 20 billion cells. Viability would be another wild card. Likely 1% to 50%.

Furthermore, because of the low viable cell count the chance of non yeast taking over the fermentation is high. In every sample of yeast from a beer bottle (including some very nice commercial beers) I have looked at under the microscope I have seen mold or bacteria. If you are culturing yeast from a bottle I would recommend either isolating by plateing or acid wash the yeast once you have several billion viable cells.

My blog and my book have lots of information on this.

 

[eastoak]

Hey!

I'm planning to do a few brews shortly, and I'm thinking of using bottled beer as my inocculant. I'm just wondering how many yeast cells would be in a typical beer? I was impatient and bottled early, so there's a few mm of yeast on the bottom of the bottles I'd be using...

I'll make a starter if need be, just want to avoid work if it's unnecessary.

Cheers,

Delaney.

are you harvesting yeast from a beer that you brewed or a commercial beer?

 

[justintime408]

My last batch I just used rayon vert dregs. Made a 500ml starter, pitched dregs. Waited a couple days, decanted, then made a new 500ml starter. Waited a couple more days. I built up to about what looked like a vile full of yeast. Then pitched whole starter into an ipa I made.
Considering its a Brett b strain I was after, I should have built up the starter bigger.
In any regard, I had a long lag time (4 days) but have had steady vigorous fermentation since.

 

[Delaney]

are you harvesting yeast from a beer that you brewed or a commercial beer?

my brew.

I was hoping to save a few bucks but I'm too lazy to do a starter or multiple starters...I'll just buy the yeast.