As a matter of interest, how many yeast cells in a typical fermentation?

[jcsweat]

Trillions? More? I know a few billion are in a typical yeast package, anybody have any idea how many would be in a typical fermentation for 5 gallons of wort? Just curious. It's got to be a lot.

 

[Henrythe9th]

yeasty's are quite smart, in fact the only creature that will only reproduce to a max density of 1 mill cells per cubic cm.. so figure out how many cm2 are in your wort and you can know how many yeasty's.
I think

 

[devilishprune]

1 cm^3 water = 1 mL water.
1 US gallon = 3 785.41178 mL.
5 gallons = 5 US gallons = 18 927.0589 mL
18 927.0589 mL * 1*10^6 = 18,927,058,900; or 19 billion-ish

Assuming that the max density thing is correct.

 

[Revvy]

If you play around with the Mr Malty Pitch Rate Calculator even just changing the the OG of the beer on the calculator will show you how many cells you typically need or just do it in your head like it looks like Devilsprune can do.

 

[devilishprune]

So, after about 2 seconds of additional looking, I realized that my answer was totally wrong. If a smack pack purports to have 100 billion active cells, you would have to have WAY more than that for 5 gallons of beer.

Back to the drawing board I guess....

 

[Revvy]

Okay, then don't do what dp does and figure it in your head..go use mr malty instead.

 

[devilishprune]

OKAY. So I found something. Here is a link for those interested: http://www.scientificsocieties.org/jib/papers/2008/G-2008-0522-552.pdf

Basically, these guys pitched 20*10^6 cells/mL and 80*10^6 cells/mL, and I'm going to use their data from the 20 because that's more of a typical pitch rate. These were 1.8L fermentations, by the way.

The lowest cell count that they had after fermentation was around 4 billion cells/mL. So...

18,927.0589 mL * (4*(10^7)) cells/mL= 757,082,356,000; about 780 billion, which seems a little better.

 

[theredben]

Hundreds of billions or low single digit trillions depending on OG. That was what I was going to post 3 hours age until my internet broke!

 

[MalFet]

yeasty's are quite smart, in fact the only creature that will only reproduce to a max density of 1 mill cells per cubic cm.. so figure out how many cm2 are in your wort and you can know how many yeasty's.
I think

Where are you getting this number? Unless I'm completely missing something, there's no way it is even close to right. I pitch all of my beers at about 1 million cells per degree plato per mL of wort (slightly more for lagers, slightly less for ales). That means a standard 1.060 ale starts with about ten to twelve times as much yeast as this number would suggest for the end of fermentation.

From there, for a final number I'd expect about a 4-5 fold increase...so 800 billion - 1,200 billion, just like has been mentioned.

 

[bullinachinashop]

Alot!!!!!!

Ha!

Bull

 

[kanzimonson]

I would like to definitively say something along the lines of "In one glass of unfiltered homebrew there are more yeast cells than:

-all the humans in the world
-all the humans WHO HAVE EVER LIVED
-all the humans WHO HAVE AND WILL EVER LIVE"

Somebody find this out.

 

[theredben]

Sorry, 6 billion + humans in the world at this moment. Maybe try it with polar bears??

 

[kanzimonson]

Well put it this way: I believe Sierra Nevada filters their beer and then adds back 1mm cells per mL for bottle conditioning. And I'm counting on homebrew having more than that. So that's at least the population of the US. So in a case of beef there are more yeast cells than all the humans living... How many more until it's the entire human population ever?

 

[kanzimonson]

Wow, "case of beef"? Kill me

 

[jcsweat]

Awesome, I was thinking hundreds of billions or possibly trillions. Funny to think about. So many little creatures. All doing your bidding.

 

[MalFet]

Awesome, I was thinking hundreds of billions or possibly trillions. Funny to think about. So many little creatures. All doing your bidding.

...or are we doing their bidding?

 

[kanzimonson]

One day we'll all go to that giant carboy in the sky, where all we have to do is eat, have sex, and swim in beer.

 

[devilishprune]

I think about fermentation more like jail for my yeast: 3 squares a day, you can only have sex with people that you live around, and you can't get out until I say so.

 

[kanzimonson]

And just like prison, you have to make beer in the same place you go to the bathroom.

 

[jcsweat]

One day we'll all go to that giant carboy in the sky, where all we have to do is eat, have sex, and swim in beer.

I just realized I would rather be a yeast cell :cross: