Really?! A 5L starter is necessary?

[schematix]

I always use the same starter wort - Pilsen DME at a 10:1 ratio by weight, measured to the gram. My experiences are in no way scientific, and I don't claim them to be. It looks like you you've done much more rigorous work on this subject so I will trust your results reflect the truth more closely than my subjective experiences.

I am going to be starting a 3-stage starter process this week (1.5L->3L->6L). During one of the stages (probably the 3rd) i'll leave one of the flasks off the stir plate and compare the resulting slurry quantity with that of one of the stirred starters and see if there is a difference.

 

[WoodlandBrew]

That sounds solid assuming that you mean you are using two flasks for one of the stages. For the comparison perhaps you want to set up your final stage just how you normally would and let the stir plate run for a few minutes to homogenize the suspension. Then pour half into another vessel that is the same size as the one on the stir plate and let them propogate side by side. The one on the plate will probably finish in a couple of days, but you'll probably want to give the one off the plate about 10 days to reach completion.

 

[eadavis80]

So - Woodland Brew - here is my question given this passage from your previous post: " The one on the plate will probably finish in a couple of days, but you'll probably want to give the one off the plate about 10 days to reach completion." - Are you saying stir plates yield X amount of cells in Y amount of time while non-stir plate starters yield X amount of cells in Z amount of time? If a stir plate just gets to X cells SOONER, I have no problem starting a starter a few days earlier.

 

[WoodlandBrew]

Are you saying stir plates yield X amount of cells in Y amount of time while non-stir plate starters yield X amount of cells in Z amount of time? .

Yes, that's a very clear way to communicate the idea.

 

[eadavis80]

Okay, so stir plates don't create more cells - they create the same amount of cells in less time. It's like burning calories on a treadmill. If I run 7.5 mph I'll burn in 25 minutes what a walker will burn in 90 or so.

 

[schematix]

That sounds solid assuming that you mean you are using two flasks for one of the stages. For the comparison perhaps you want to set up your final stage just how you normally would and let the stir plate run for a few minutes to homogenize the suspension. Then pour half into another vessel that is the same size as the one on the stir plate and let them propogate side by side. The one on the plate will probably finish in a couple of days, but you'll probably want to give the one off the plate about 10 days to reach completion.

I have 5 x 2L flasks so to up the volume I add flasks to my quad stir plate.

Step 1: 1 Flask x 1.5L each = 1.5L
Step 2: 2 Flasks x 1.5L each = 3.0L
Step 3: 4 Flasks x 1.5L each = 6.0L

Point taken about homogenizing it. I think at this point i'm just going skip the experiment since I can't really execute it properly. No sense in adding data that didn't come from a well controlled experiment.