Correct yeast counts?

[enricocoron]

I've been looking through some texts and the common logic seems to be 5-15 million cells/mL. One could guess the lower end is for 5% top fermented ales, the middle of the range for lagers and stronger top fermented ales, and the top of the range for dopplebocks and very big top fermented beers like Barley wines or Belgian quads.

I called white labs about their custom pro brew pitches, figuring they would be in this range. I was surprised to find out that their pro pitch rates are 2.2 -4.4 million cells per mL, yes they report a variability in their counts with that big an error margin.

When I plug in a 1.061 OG porter to beersmith it recommends 11 million/mL. Now I think that is a little on the high side to be sure, as most pitching calculators are, but somewhere in the 7-8 million/mL range seems right. What number would you use? Do you think the software overpitches a little because the programmer assumes that you will underoxygenate? This would be a robust porter mashed at 154 and pitched with WLP007 at 64 free rise to 67 and hold 3 days then free rise to 70 until it drops.

 

[diS]

Standard pitching rate for ale is 0.75M/ml/°P.
In your case it gives ~11M/ml and I would go with this number.
I dont know why White Labs use such small number (assuming they use it for normal strength beer)... even C. White in his book mentions 0.75M as standard rule.

 

[enricocoron]

The calculators all use this pitching rate I think. What Chris White cites and what he sells appear to be two different animals.

Anyone want to double check the math. I was told by WL that a 7bbl pitch was 1.8 Liters volume with cell density of 1-2 billion/mL and that would be fine for worts up to 1.060.

 

[diS]

7bbl= 820,000 ml
With density od 2B/ml in 1,8L there is 3600B of cells.
According to that (3600B= X * 15°P * 820,000ml) their pitching rate for 1.060 wort is ~0,30 M/ml/°P, that number decrease in half for 1B/ml density.

Am I missing something or they regularly under pitch?

 

[enricocoron]

They suggest to customers that they pitch this rate. Their beer at their own tasting rooms is apparently not good. The take the same wort and pitch with 3-4 different yeasts so you can see the difference but two of my brewer buddies have said the beer in general isn't very good so you don't get a lot of info out of it.