to step up or not to step up yeast starter?

[soggycd]

I recently got a 4 L flask for lager yeast starters so I do not have to worry about not having enough yeast in my 2 L flask.

Now I am wondering if there would be any added benefit to doing a 2-step starter, in which I start with 1-2 L of wort, ferment, and then add more wort to a final volume of 4 L, versus just knocking up 4 L of starter from the get go.

Does anybody have any insight on the matter? In other words, given a final starter volume, is it better to step up to that volume in increments or just do one step using the final volume from the beginning?

 

[dinnerstick]

use a yeast calculator that allows you to do steps. this one is popular
http://www.yeastcalc.co/yeast-pitch-rate-and-starter-calculator
that will take away any guessing. the goal is to get the number of cells needed, either way works fine.
then do what is most convenient for you. lager yeasts can take a while to flocculate after they are done, and they tend to taste nasty at high (room) temp, so if you are going to decant the supernatant before you pitch, factor that into your schedule, you will be doing it each time you step up the starter and it can take a few days.

 

[soggycd]

Yeah I did a poor job of explicating my question.

I might be using "step up" in a different manner than usual. Usually by stepping up people mean feeding yeast a given amount of volume, crashing, decanting, and then adding more wort for more growth. My impression is this is what most step up calculators assume and I am familiar with the process; crashing and decanting lager yeast multiple times to get enough is a pain IMO.

I am not concerned with crashing and decanting. I am wondering if there is any benefit to adding a total volume of starter wort in increments without crashing and decanting. For example, if I add 2 L of starter wort, ferment out, and then add 2 more L of wort without decanting the first two. Would such a routine yield any different results from inoculating the total 4 L of wort from the very beginning? I imagine adding the wort in increments might yield a little healthier yeast, but my main concern is the possible effect on count.

 

[Cyclman]

My understanding is that you want to do as large a starter (assuming you're starting with a vial or smackpack) as reasonably possible. So, a 4L starter will produce more yeast in one step (brewer's friend calculator, using braukaiser stirplate calculation) than a 2L then another 2L 2-step starter.

Yeast love to grow in an oxygen rich environment like a stirplate.

 

[AerationStation]

If you don't decant the starter between steps just make sure to up the OG a little when you make the new wort. The extra fermented wort in the flask will dilute the new stuff. Past that I've never stepped without decanting before so I don't know what to expect

 

[soggycd]

My understanding is that you want to do as large a starter (assuming you're starting with a vial or smackpack) as reasonably possible. So, a 4L starter will produce more yeast in one step (brewer's friend calculator, using braukaiser stirplate calculation) than a 2L then another 2L 2-step starter.

Yeast love to grow in an oxygen rich environment like a stirplate.

Thanks cyclman, this is what I was looking for. I could have sworn I tested the same thing on multiple calculators and got contradicting results, which is why I posted here, but I went back to check your reply and I must have misread and or mistyped something before, because it seems you are correct. I am glad, the less work the better!