stepping up starter methods

[krenshaw]

i'm debating on doing some larger beers in the future and wanted to see about larger starters, especially if i am able to do a lager someday.. i have a 2L flask for my stirplate.. now i've done starters many times before, but never stepped up them to get them larger.. can i do something like this to make a larger starter with this sized flask, and will it make much of a difference?

- put 1.5L of starter beer (water/dme) in the flask and pitch the yeast as usual
- let it do its thing for 48 hours or so
- cold crash it and decant most of the top off
- prepare another 1L or so of starter beer, cool and pour into the flask with just the slurry
- let it further do its thing for another 48 hours
- cold crash it and decant most of the top off

i've done the first 3 steps all the time, never tried adding more.. would doing this multiple times effectively make a larger than 2L starter because though i only have a 2L flask, i'm still propagating (is that the correct term?) more yeast each time i decant and refill?

 

[cyclonite]

Unfortunately it doesn't work that way. You'll need to increase the amount of starter wort each time you step up, otherwise you won't get any new significant population growth. Instead, the same population will just continually eat all the sugars you throw at it and then go dormant. So, for example, when I harvest from a few bottles, I start with a tiny starter about 200 ml, let out ferment, then pitch into a larger one say 800 ml, then a third and final of about 2000 ml.

 

[rjsnau]

Most homebrew shops have a 1 gallon glass jug for like $6. That is what I use. Makes it a bit more difficult with a stirplate since the bottom is not flat but I can get it to work.

 

[krenshaw]

i could probably use a growler, but then i'd run into the same problem of the bottom not being flat.. thank for the info, once i have a recipe in mind i may have to buy a bigger vessel, but i do have a 1L and 2L ones, so i could easily step up a little between the two.. i'm thinking of doing that with some yeast from a couple bell's bottles for my two hearted clone i want to do next

 

[webgodhog]

I have a 2 gallon plastic fermenter that I use for this exact purpose. Midwest has them for $5. The bottom "ring" that supports the fermenter is wide enough to fit over most stir plates.

 

[tomCT]

You might want to take a look at yeastcalc if you are not familiar with it. It is similar to Mr. Malty, except it will also give you pitch rates for stepping. Easy to use.

Link: http://www.yeastcalc.com/

 

[william_shakes_beer]

Unfortunately it doesn't work that way. You'll need to increase the amount of starter wort each time you step up, otherwise you won't get any new significant population growth. Instead, the same population will just continually eat all the sugars you throw at it and then go dormant. So, for example, when I harvest from a few bottles, I start with a tiny starter about 200 ml, let out ferment, then pitch into a larger one say 800 ml, then a third and final of about 2000 ml.

soooo...

How does this brainless single cell organism figure out how much fermentable sugar is available and determine whether or not it is time to have an orgy?

I take your statement as correct, just don't understand why.

 

[samc]

If you ate all the food in the world, then had children - what would they eat?

 

[krenshaw]

well my point was once they had children, i would introduce more food again possibly creating more children.. sounds like the argument is that when i introduce food again that would only be enough to sustain the yeast number, not let them keep growing.. seems counterintuitive to me, though i know nothing about yeast really which is why i was asking

 

[cyclonite]

My understanding (I'm no expert either) is that they will eat the sugar faster than they can reproduce, which is why you will not get any significant population growth (you will get a little, but not enough to step up the population). Hope that makes sense.

 

[Billybrewer09]

Here is an idea. Now keep in mind I have never tried this.
Make your starter and step it up one time. Cold crash and decant. Now split your yeast cake in half. Step up half your yeast twice. Crash and decant and save in a jar. Then take the other half of your original starter and step it up twice. Crash and decant. Add all the yeast back together and pitch.
It seems that this would work.

 

[acefaser]

Watch This Video. It describes the step-up method found in the book Yeast by Jamil Zainascheff and Chris White.