Dry yeast cell count..

Hi!

And hello from Finland…joined as " support " to AHA association because the site is just great…

So im using SAFLAGER S-23 11.5 G yeast for my next beer and i found from the Fermentis site, that it consist 6 * 10to9  " Viable cells at packaging: per / g " , so one  g consist 6 billion cells and 11,5g pack contain 69 billion cells,right?
My target is 1.051 and pitch calculators give me need of 300 billion for my 16l ( 4,2gal ) batch, and recommend
1 1/2 11,5g packs of dry yeast for the batch…
Where do i go wrong when i calculate that allmost 4 packs is needed for the batch using the Fermentis formula.??

I don’t concentrate on the cell count, but I do know that the practical limit for ales is roughly 1 packet per 20L for 1.065 wort. You can use that for lager too, but then you run the risk of developing more fermentation by-products. Most pitch roughly 1.5 to 2 times that amount for lagers.

I’m sure that someone else will evaluate your math.

A safe bet may be to “split the middle” so to speak and assume somewhere between 12-14B/gram of dry yeast.

20B/gram seems excessive and 6B/gram is a known conservative value.

Based on my learnings from the second half of the following thread, I think one pack is enough for your batch, especially if you rehydrate in plain tap water or spring water.  You could go as much as 1 1/2 packs if you do not wish to rehydrate.  More packs than that is severe overkill.

https://www.homebrewersassociation.org/forum/index.php?topic=27438.msg361722#msg361722

Thanks for the answers…

Found a dry yeast pitch calculator that geve me 288 bil cells to that patch and 14g of dry yeast to pitch in…
Sounds like the right amount to go with…

There is a huge discrepancy ion the cell count that dry yeast manufacturers report.  That is compounded by people like Beersmith and Palmer repeating info with out checking.  In doing research for our next book, I found that it varied widely from manufacturer to manufacturer, with much literature directly contradicting what the manufacturer says.

So instead of speculation… no one has just counted them?

Apparently the manufacturers have.

Which is the speculation…I guess I need to do it then?

If we’re making good beer, we don’t need to count yeast cells with microscopes.

Fully agreed. But if the part of the hobby that you enjoy is all the tiny details, by all means count away

I don’t understand…if they’ve done it, why do it again?

This is the age old (in homebrew Times) argument though. Manufacturers underestimate somewhat  and calculators way overestimate.

I think the answer is in the 10-14B/g range somewhere.

I will do a few counts next week if I have time. Be interesting to see what differences there are.

Because I don’t blindly follow something some one tells me. [emoji4]

If they sell dry yeast by weight, won’t the cell count vary by strain (and manufacturer for that matter) due to differences in the mass of the single cell?