Hey everyone,
Forgive me if this is a repeated topic, but a quick search didn't find anything similar.
Yeast viability (ie, healthy cell counts) is an important part of homebrewing. Specifically, it's important to pitch the correct number of cells into your wort by creating properly sized starters (FWIW, I'm ignoring the vitality argument for now). There are numerous calculators that help you figure out your starters, like Mr Malty's, Homebrew Dad's, and the one right inside Beersmith.
These calculators generally use the following inputs to calculate your ideal starter size(s):
Now you have much more accurate information to plug into your yeast viability calculator. Looks like I need a multi-step starter.
Without this method, I would have underestimated my original cell counts by almost half (100b versus 59b).
For what it's worth, White Labs aims for 1.5e9 to 3e9 cells/mL for each batch. A few brew days ago I got a batch that was over 4e9 cells/mL in a PurePitch, and reasonably fresh, so I had over 150b cells on brew day. Don't just assume 100b!
Has anyone else used this method? While the 100 billion cell assumption might get you close, the QC information is free. Why not use it?
Thanks for reading. Any thoughts?
Forgive me if this is a repeated topic, but a quick search didn't find anything similar.
Yeast viability (ie, healthy cell counts) is an important part of homebrewing. Specifically, it's important to pitch the correct number of cells into your wort by creating properly sized starters (FWIW, I'm ignoring the vitality argument for now). There are numerous calculators that help you figure out your starters, like Mr Malty's, Homebrew Dad's, and the one right inside Beersmith.
These calculators generally use the following inputs to calculate your ideal starter size(s):
- Original gravity of your wort
- Date of yeast manufacture (assuming some loss of viability per month, usually 20%/mo)
- Original cell count (usually 100 billion for liquid, and 200b for dry)
- Go to https://www.yeastman.com/Login/Public/Report/PublicLabQCResult.aspx
- Type in your Lot Number (In my example, I have a tube of Yeast Bay Wallonian Farmhouse, lot number 1027066)
- Look at the row titled "Cell Counting" (Example, this lot says 1.68e9, which is 1,680,000,000 cells/mL)
- For the old plastic hard tubes, multiply by 35 mL; for the new PurePitch, multiply by 40mL (Example, 1.68e9 * 35 = 58.8e9 = 58.8 billion cells)
- Note the lab test date (Example, 7/2/2016)
Now you have much more accurate information to plug into your yeast viability calculator. Looks like I need a multi-step starter.
Without this method, I would have underestimated my original cell counts by almost half (100b versus 59b).
For what it's worth, White Labs aims for 1.5e9 to 3e9 cells/mL for each batch. A few brew days ago I got a batch that was over 4e9 cells/mL in a PurePitch, and reasonably fresh, so I had over 150b cells on brew day. Don't just assume 100b!
Has anyone else used this method? While the 100 billion cell assumption might get you close, the QC information is free. Why not use it?
Thanks for reading. Any thoughts?