How long per step in a yeast starter

Beer Foundry

Member
Premium Member
Joined
Jan 7, 2018
Messages
31
Reaction score
35
Points
18
I’ve searched to see if this has been discussed before so apologies if I have missed it. I have just invested in my first stir plate and 2 L flask so that I can try yeast starters.

I can see from the online calculator that I need to use two steps. The first one has been running for 24 hours and there are bubbles on the surface.

The question is, how do I know that the yeast has stopped growing so that I pour off the wort and load up with a fresh DME solution? is it just a matter of time? Or should I stop the stirring and gauge how much yeast there is when it settles?

thanks everyone
 
The idea is that the yeast ferments the wort and so also reproduces. Since you don't care how the result tastes, you let it ferment faster than usual. As soon as most of the fermentation is done, it's time to let the yeast settle out and either use it or, as in your case, do it again.

I generally stir for 12 hours and let it sit for 12 hours, then cold crash it, wait a couple hours, and decant the liquid to get the yeast.

So if the yeast is about done, it's time to let it settle out for the second step. Too early and you miss a couple of yeasties (no big problem), too late and you spend more time than necessary (again, no big problem). Somewhere in between is the goal. (Technically, you can tell it is done using a hydrometer, but to waste yeast on a sample...ugh.)

Bottom line: 24 is plenty, let it settle out now.
 
Thank you @Donoroto. Great advice. I’ll turn off the stirring now and let it settle and do the second stage tomorrow.

Thanks and I will drink to your health.
 
Thanks @sbaclimber too. I’m guessing you’re advocating something in the mid 20s C to accelerate yeast growth?
For speed, yes.
I ferment my lagers at ~9°C and have done a handful of starters at that temp. They turned out fine, but took ages (3-4 days +) to finish fermentation. At room temp. (~20°C) a day or two and it is good to go! :D
 
And the fact that bubbles are still rising so the yeast is clearly still active, isn’t a sign that I should let it go on for longer? I suppose it’s not like when it’s in the fermentation vessel and you let it go until it is exhausted. You’re trying to stop it while it is in prime condition, correct?
 
Just watch for the krausen drop off. When your starter is done you'll have no foam on top.

Remember one starter varies from one another;) yeast type- cell count- viability- temperature ect ECT.

If your keeping the supernatant just pitch the lot.
If you want to pitch just the yeast you then chill it for 24 that'll separate it pretty good.
 
@Trialben - “supernatant” - great word. Had to look it up. Every day is a school day!

supernatant
/ˌsuːpəˈneɪt(ə)nt/

TECHNICAL

adjective
  1. denoting the liquid lying above a solid residue after crystallization, precipitation, centrifugation, or other process.
    "carefully transfer the supernatant fluid into a 15 ml centrifuge tube"
noun
  1. a volume of supernatant liquid.
    "the supernatants were filtered and analysed
 
@Trialben - “supernatant” - great word. Had to look it up. Every day is a school day!

supernatant
/ˌsuːpəˈneɪt(ə)nt/

TECHNICAL

adjective
  1. denoting the liquid lying above a solid residue after crystallization, precipitation, centrifugation, or other process.
    "carefully transfer the supernatant fluid into a 15 ml centrifuge tube"
noun
  1. a volume of supernatant liquid.
    "the supernatants were filtered and analysed
Ah don't you just love big sciency words! It sounds better than what it is the resulting left behind substance.
I suppose in reference to above post supernatant is sometimes the material you want to keep.

Personally regarding starters I've pitched it whole and decanted either or but I'd be more inclined to pitch the lot on an ale;)
 
Oooohhh! Big word! You bet I'll find a way to use that one. Supernatant. Love it! I always pour the supernatant liquid off of my starters before using them....
 
Just watch for the krausen drop off. When your starter is done you'll have no foam on top.
Not sure if it is just me, but with a stir plate at <9°C there is virtually no krausen to speak of...
I also just had to turn the plate off and look at the bubbles. Once they appeared to be slowing down a bit, I cold crashed.
 
Why do you have the stir plate <9C? It's a starter, do it at room temp and hammer on.
 
Why do you have the stir plate <9C? It's a starter, do it at room temp and hammer on.
Only reason was, the stir plate was in the basement....and it got cold.
I just moved the stir plate upstairs and spun up a new starter. Definitely a lot more krausen! (it is really fresh yeast...)
 
Valid reason. My basement stays at around 18-20C all the time unless the furnace quits so I never go that low. Doing it warmer will definitely get you results faster though.
 
Krausen now died down and bubbles slowed. Took 48 hours but now cold crashing in the garage with forecast 0 deg C overnight tomorrow if I can wait.

I’ll boil up another 2L of DME solution ready to do step 2 and then brew my saison at the weekend hopefully with 600bn cells ready to go to work. Woop woop.

BTW, ref the supernatant definition - who knew centrifugation wasn’t a made up word either!
 
That's a lot of yeast for a Saison, for a 5G Ale I usually just do a single 2L step unless the yeast is really old. My understanding is lots of yeast in a Saison could actually make it taste less Saisony.
 
That is probably fine then, I was doing 42L batches for a while but stepped it down cause I couldn't drink that much.
 

Back
Top