Pitching rate "rules of thumb"

[EscapeArtistBrewing]

Where do the "standard" pitching rates for lagers vs ales come from? General consensus over time and trials? Or, Is there a definitive spec (published study) "out there" for the rates (.75M cells/ml-°P for ales, vs. 1M for 1.060 ales vs. 1.5M for lagers)?

Finally, for a given style classification, the number of cells is tied to the SG of the wort; is there a formal relationship between cell number and gravity?

 

[jdauria]

I think it was a combo of general consensus over time by professional brewers and work done by mathematician and homebrewer George Fix who wrote Principals of Brewing Science. Can you make a ale or lager by not hitting those rates, sure, but lag time will be longer and attenuation may be less.

Not sure on your second question.

 

[EscapeArtistBrewing]

Not sure on your second question.

What I had in mind was a formal (as in formula) derivation of values seen in charts such as this one found on this page.
When I see tables like this:

I start thinking about an equation to fit pitch rate to gravity, but if it's all based on experimentation and best-practices (thanks @jdauria), then I'll just stop at the chart.

 

[Indian_villager]

To throw another source of information to confound the whole thing is the varying cell count/g(biomass). Are we to target a biomass or a cell count? Based on the attached, I don't think there is any accurate way of targeting cell count short of picking up counting equipment.

https://omegayeast.com/uploads/downloads/OY-Hombrew-Brochure-Final-Web.pdf

 

[jdauria]

To throw another source of information to confound the whole thing is the varying cell count/g(biomass). Are we to target a biomass or a cell count? Based on the attached, I don't think there is any accurate way of targeting cell count short of picking up counting equipment.

https://omegayeast.com/uploads/downloads/OY-Hombrew-Brochure-Final-Web.pdf

Agree with that. Pitch rate charts and calculators are only estimations and and only way to accurately know is via cell counting.

 

[Indian_villager]

Agree with that. Pitch rate charts and calculators are only estimations and and only way to accurately know is via cell counting.

And on top of that you can still vary that number to get the yeast to be more or less expressive depending on the strain. At some point the buggers will get stressed to the point of bad beer, unless apparently its kveik.

 

[IslandLizard]

You're probably aware of this yeast pitch/growth calculator:
https://www.brewunited.com/yeast_calculator.php

Together with applying some common sense it delivers decent approximations, usually good enough for homebrewing.

 

[Bramling Cross]

Digging through the cobwebs in the back of my mind, I believe the first time that I heard about homebrewers writing formal yeast calculator tools was on the old Home Brew Digest forum in the late '90s. There were two guys in particular that developed early tools. I've been wracking my brain trying to remember their names for about an hour now and I just don't remember. There's no easy way to find out because that old forum has long since died to software obsolescence.

Around the turn of the millenium, Jamil Zainesheff published his Mr. Malty calculator and that gained some serious traction and everyone was suddenly obsessed about cell counts. But cell count mania seems to have died off a bit over the past decade as we seem to be returning to the old volumetric and viability yardsticks that were prevalent prior to the advent of the yeast calculator tools.

Don't take anything that I've written above too seriously, I'm going off of memory. Worse, as a guy with a very pragmatic approach to brewing, I wasn't hugely involved in the cell counting movement and paid them more ridicule than actual attention back in the day, so I'm hardly a reliable source on this matter. Nevertheless, I've done my best to remember what I could. I hope it helps a bit.

 

[MaxStout]

I used to use Dustin Sullivan's Yeastcalc, the flash-based calculator. You could even download the program and run it on your desktop. I probably have it somewhere on my hard drive. It's still online (yeastcalculator.com), just with an updated interface.

 

[BrewnWKopperKat]

There's no easy way to find out because that old forum [Home Brew Digest] has long since died to software obsolescence.

This reply is mostly for future readers curious about Home Brew Digest. There's no easy way to search the online archives for "two guys who developed the early tools".

It [Home Brew Digest] hasn't totally disappeared.

Internet Archives "Wayback Machine" did capture it. Here is a link to the "Index For The Homebrew Digest" that was captured in June 2010. (For those not familiar with the "Wayback Machine", on any page you can navigate forward/backward through time. The page I mentioned has 161 captures from 15 Nov 2000 - 12 Feb 2025).

 

[Bramling Cross]

This reply is mostly for future readers curious about Home Brew Digest. There's no easy way to search the online archives for "two guys who developed the early tools".

It [Home Brew Digest] hasn't totally disappeared.

Internet Archives "Wayback Machine" did capture it. Here is a link to the "Index For The Homebrew Digest" that was captured in June 2010. (For those not familiar with the "Wayback Machine", on any page you can navigate forward/backward through time. The page I mentioned has 161 captures from 15 Nov 2000 - 12 Feb 2025).

Thank you for doing that. I was cooking dinner at the time and was too lazy to bother, in large part because I learned that Bill Pierce had passed away while digging around for the remains of HBD.

I had my suspicions because I hadn't seen hide nor hair of him in, well, a very long time. I might dig through the archive to find his obituary this weekend. For those of you that don't know who Bill was, he was a consummate gentleman, very knowledgeable, and a very kind and reasonable man. He was a moderator on HBD during the wild and woolly days of the early online homebrewing scene. He taught me a lot and I owe him a lot. He was a good man and he didn't deserve to be condemned to have to preside over the #(%*# show that was prime HBD.