Question about planning yeast propagation.

[osoliver]

My plan so far is to inoculate starters from yeast slants and propagate them to pitchable quantities. My question is how do I estimate the required volume of the final step up to hit our ideal pitch rate. I tried yeast calculators but I'm unsure what the first cell count will be after inoculating from a slant. Do I need to do a test run to get an idea of how much volume will be required? Looking to find out what size of equipment will be required for this. Any help is appreciated!

[gitchegumee]

#1: Why? Why would you want to do this outside of a larger production brewery, or proprietary strains? You likely have access to very good strains of dry yeast which-besides not requiring oxygenation-also don't need you to do cell counts. Weigh it, and dump it. Then move on to the million other things you don't have time for.

#2: You just and simply cannot do what you propose without counting cells in a representative yeast slurry sample. You would also need to include viability assessment. It is not possible to calculate yeast simply by adding a volume of media and expecting to grow x many yeast. So besides expensive lab equipment, cleaning, maintenance, reagents--not to mention banking your own yeast slants; your most important asset is your time. This endeavor will take plenty. Far too much for a small brewery to be worth it.

There are so many other things that will be much more important than fussing about with yeast, that you would be wasting your time with this IMO. It might sound fun in the beginning, but spend a few weeks in a brewery QC lab and get back to me about that. IMO, dry yeast is the best thing to happen to small brewers regarding time savings. Excellent beers are possible with very little time spent on yeast handling. Best of luck!

[osoliver]

Thank you very much for your response and input. Our plan definitely includes doing cell counts and all that good stuff. I'm more looking for how I should go about sizing equipment for propagation (i.e do we need a 15 gal. keg brink or a 1 bbl propagation vessel). Will we have to do a test run to get a rough idea of the equipment that will be required, or is there a better way to go about this? I believe this venture is suitable for us because lab-ready yeast can be quite costly where we are located in Canada and we are not brewing frequently enough to repitch very often. Thanks again, I appreciate your time. Cheers!

[gitchegumee]

Yeast propagation vessels are available. There are many techniques to utilize them, and one size doesn't fit all. You need to select a propagation method before you can size your vessel. You may propagate enough for an entire brewlength, or a partial fermenter--using the fermenter as a last propagation vessel. If your yeast strain has special flavor characteristics that are highly dependent on pitch rate, then you need to be far more precise in your pitch rate. If you are not brewing frequently enough for repitching, then your situation really begs the question: why would you not use dry yeast? Easy solution for great results and less time.