So I was having a discussion about starters with someone, after reading NB's Yeast Pitching Rates document. In which, I read that, with a stir plate, and considering a two stage propogation, I could get 453B cells with two .5 litre stages.

However, It was brought to my attention that in Jamil's yeast book, he argues that sub-litre starters are pointless.

How can I reconcile this? Which resource is right?

  • I do not have Jamil's book, so I can't check the reference myself. I wonder if, perhaps, he's only speaking to a single stage starter? The NB document indicates that in a single stage, you'd still nearly double your count, so, the two resources really are at odds with eachother. – reidLinden Mar 24 '11 at 13:09

I would certainly follow JZ's advice over NB's. While I know and respect the people at NB (hey, they put out kits of my recipes!), I know for a fact that JZ has worked with Chris White to do detailed studies while NB is just repeating commonly held "wisdom". You're also comparing apple to oranges since NB recommends 2 steps and JZ is talking about a single step. A 2 step starter is not only more hassle, you double the chance of accidentally picking up a contamination. In addition, if you don't feed the yeast enough wort initially, they have nothing left to help them build glycogen reserves at the end of starter fermentation which are used to help the yeast get off to a healthy start once you pitch it into your beer.

  • Thanks Denny, This pretty much matched my 'gut-feeling', but I was hoping to get someone else to reconcile the differences. I'm quite satisfied with this answer. – reidLinden Mar 24 '11 at 15:47

Your goal is to achieve an approximate doubling of the healthy, viable yeast cell count. So the important thing is the ratio of yeast cell count to wort volume. Too little wort and you have just fed the existing yeast, but they've eaten all of the sugar and nutrients before they've all had a chance to reproduce. Too much wort, and you've got beer.

If you plot the numbers that you see on NB's pdf, you'll see that what you get is a curve, which appears to mimic the numbers from Jamil's yeast book. They're a little different, but they're close enough to make me think it's just differences in experimental methods. (edit: turns out that the experiment from the Yeast book was done with no additional oxygen and no agitation, so it may be that both are correct)

If you have 2 containers that will hold .5L, you could make a liter of wort and split the vial somewhat evenly between the 2 smaller containers. That's what I do when I need to make larger starters. For really large starters, make a small beer (under 1.050), and then pitch the yeast cake from that into your big beer.

  • I've only got a single 1L flask, so I'm actually looking at the 'serial' process mentioned in the NB document. – reidLinden Mar 24 '11 at 13:39
  • mrmalty.com/calc/calc.html zainasheff's pitching rate calculator may help, though it doesn't take into account a stepped starter. – baka Mar 24 '11 at 14:01
  • yeah...I've looked at it, but not having the stepped increments, its only of limited value with such a small flask. – reidLinden Mar 24 '11 at 14:27
  • homebrew.stackexchange.com/questions/967/… Do you have any milk or water jugs laying around? – baka Mar 24 '11 at 14:33
  • yeah...I've got a gallon jug (glass even) that I could use, but its just not as convenient as using a nice erlenmeyer flask. – reidLinden Mar 24 '11 at 14:55

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