I understand how to make a yeast starter but for a 2 stage (which I never have needed to do) for the second stage It appears that I don’t need to add any yeast, just make the next little beer (water and DME) and put it in with the original yeast for the 1st starter to make the necessary amount. Does this sound right?
So I can get by with only one smack pack of yeast to make maybe over 400 billion cells of yeast?
Correct. Decant the spent wort from the first round before adding more.
Although if I needed 400 billion cells starting from a pack, I’d just make a 2.5 L starter.
nice idea about 2.5 L wort. I think I have a gallon jug or something to do that in.
Would I only use one smack pack for the 2.5 gallon of starter?
would there be any problem with using a Growler? The neck is kind of small.
Another way is to pitch yeast that are active into well oxygenated wort. If they are in exponential phase the difference between 200 and 400 billion cells is about 90 minutes.
I’ve never found the first-stage-starter decanting to be necessary unless I need the extra volume/head space. Is there a good reason why it would be from your perspective?
Pragmatic!
Mainly space reasons
Dilution I’m guessing. When I step up yeast I don’t decant either, but I’m going from slant to 20ml to 200ml to 2L. 10% isn’t much dilution and you can just bump the °p up if it freaks you out too much.
I wonder about staged starters when people are pitching 100ml to 1L, decanting and adding another 1L. At some point it seems the growth will not be what some expect because the yeast amount will be getting close to max for the volume anyway. I know I get great growth with 1:10 and probably could go 1:20 if the nutrients are there.
Edit: Denny was typing while I was. Lol
Probably the best way to get a huge pitch is to brew a session beer…
^^^^This is my preferred route. It’s about the only time I make a small batch of lager beer.
What he said.
Yes, listen to Jim. For the nth time, I miss having Mark on here. Can we sticky some of his posts?
+2 or something. This is also an effective, practical way to grow yeast. If I want a Scotch Ale brew a 60 shilling and pitch the cake into the Scotch Ale.
That’s a good point that is probably often missed. I believe the max is 200B per liter. If you’ve already got 200B cells, you aren’t going to grow more by decanting them into another liter of wort - yet another thing I learned from S.C.
[emoji6]
This is my first post, I just registered after reading about 50 pages of yeast starter threads because I wanted to join the conversation. It seems Mark is gone now?
When propagating a starter, do we assume a well-oxygenated (dare I say SNS) starter will always reach maximum cell density of 200b cells/L if the inoculation rate is reasonable?
I’ve got a 100-day-old pack of 1764 that I’m going to start with 2L of 1.040 wort for an 11 gallon CDA (two 1-L starters each with half a pack of yeast). Assuming a high-end estimate of 20% loss of viability per month, I figure I can reasonably expect 50b live cells total, or 25b per starter jar. Is it safe to also expect that I’ll reach that max cell density of 200b cells in each starter after 3 doubling times of 90 minutes, plus a little while to get rolling after inoculation?
Maybe… too many variables to say for sure. How high is the gravity of your CDA?
The CDA is 1.064, but I’m asking about the starter yeast population. In all the reading I did this weekend, everybody (mainly Mark) only refers to max cell density, but I never could tell if that was a given. It seems it should be, if nothing is limiting the yeast growth.
In other words, when we plan yeast starters, do we plan assuming every liter at (or beyond) HK will contain 200b cells? I am pretty sure that’s how most of us understand it, and it makes starter calculations a lot simpler in my mind.
Frankly, since learning from Mark, I don’t care about yeast cell counts anymore. For 6 gallons of 1.065 ale or lager I build one 1L oxygenated starter morning of brew day, I give ale starters 8 hrs to hit exponential phase, and lagers 12 hrs. Then I pitch the whole thing. The thinking being that at exponential phase you are only ~90 minutes from doubling. So the difference between 200 billion and 400 billion is 90 minutes. My beers always show airlock activity by the next day