Yeast Viability w neglected starter

Hey, so on 3/31 i started a 2L yeast starter from top cropped WLP 1272.

Kept it shaken ever 1-3 hours or so for the first 3 days and then my work schedule changed for my anticipated brew day, and there it sat. I hadn't done anything with it thinking itd be trash, but I remembered reading in "yeast" about storing a yeast cake under the beer it brewed.....can I still use this? If so, what should I do to prep it for pitching?


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How much yeast actually went into the starter? There is such a thing as under-pitching a starter.

I would expect to see at least 1/4" layer of yeast on the bottom of that container if you pitched at least 100 Billion yeast cells to the starter.

Personally I would decant off the liquid and pitch the slurry to another large starter and if it gets high krausen within 12 hours you should be good to go with it! A bit more DME is cheap compared to messing up an entire batch of beer by not pitching enough yeast.

I top cropped with a stainless steel spoon, it's only the second time I've done that. How do you know how many cells are started with when doing this?? Sorry for what I'm sure is a very novice question...
I knew it was necessary to improving my pitching/culturing skills just haven't gotten that far into my learning yet.


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Well when you top crop it's hard to judge exactly how much yeast you have but in general 1 tsp of nearly pure yeast will have about 20-25 billion yeast cells. When you top crop krausen you also have foam and trub so I would be conservative and assume only 10 billion cells per FULL teaspoon of thick yeast slurry.

The average gravity ale (say 1.055 OG) needs at least 200 billion yeast cells pitched for a clean and full fermentation.

This is a great tool for estimating how much yeast you need. http://www.mrmalty.com/calc/calc.html

zhubbell said:

Hey, so on 3/31 i started a 2L yeast starter from top cropped WLP 1272.
View attachment 192262
Kept it shaken ever 1-3 hours or so for the first 3 days and then my work schedule changed for my anticipated brew day, and there it sat. I hadn't done anything with it thinking itd be trash, but I remembered reading in "yeast" about storing a yeast cake under the beer it brewed.....can I still use this? If so, what should I do to prep it for pitching?


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Click to expand...

Refrigerate your starter for a couple of days to drop the yeast out of suspension. Calculate a step up starter per Jahems advice.

Alright - starter moved to fridge. That's perfect because Im looking to brew in a few days. Looking very much forward to learning more towards having more successful fermentations!

Anybody recommend a good stir plate? That's my next investment. Looking to go fairly economical, but also very effective. I don't want to be sorry in 6 months because I want a new one after finding out mine is dramatically inferior, or not doing the job. I don't need to make huge starters, I only have a 10g mash tun, so I don't brew huge batches, and I don't forsee that changing anytime soon.


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If you are in a hurry check out e-bay and search with Google. I remember a person posting here that he built stir plates using a computer fan. Same as DIY projects on the forum. He was selling for $40 and an excellent warranty.
Or look it up here and build your own.

I built my DIY stirplate for $5.

Used an old computer fan and hard drive magnets (free) and a piece of thin plexi I had laying around for a surface and the stir bar was $5 on Ebay. Best purchase ever. My starters grow 2X as much yeast in half the time as with intermittent shaking.

Another vote for building a stirplate. It's cheap and pretty simple to do. You will spend a bit of time getting the magnets centred properly, but once you're past that it's just amazing to have. And not really worth $50+ shipping, at least in my mind.

Alright, I have all the computer parts and an old cigar box, how's this look for a stir bar? Is this what I want?


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Same style and size stir bar I use most often. Works very well.