Airating a Starter

[chugly]

I need a 4L starter, was going to make the first 2L @ 1.040 like normal aerating the wort. Next step I was going to make 1.5L of 1.040 wort in which comes to my question should I airate the starter again (knowing that once I get fermentation oxygen is not desired), or is this so little of an amount compared to 5.5gallons I am making that it would not matter. lastly, I will do the last .5L or 500ML the night before brew day, same question as above.

Thanks in Advance,
Chugly

[brewinhard]

I need a 4L starter, was going to make the first 2L @ 1.040 like normal aerating the wort. Next step I was going to make 1.5L of 1.040 wort in which comes to my question should I airate the starter again (knowing that once I get fermentation oxygen is not desired), or is this so little of an amount compared to 5.5gallons I am making that it would not matter. lastly, I will do the last .5L or 500ML the night before brew day, same question as above.

Thanks in Advance,
Chugly

Why not make your first starter step (2L), aerate, let it ferment out, then cold crash overnight. Decant the spent wort leaving behind your yeast sediment and add your fresh wort on top. Aerate, let that ferment out, cold crash the night before brewing. The morning of your brewday, decant your latest round of spent wort, and top off with your last step of 500 mL or so and pitch that active starter at high krausen (if that was what your original plan was).

That is at least how I would handle it, but maybe someone else will chime in with some other ideas.

[Klickitat Jim]

I prefer at least doubling as I step up so im giving them a reason to double. But if you are using a 100ml pitch to start with, I would just go with 4L one step and 1.040 max. My starters are 1.030 or less. Im all about low osmotic and whatnot.

If you do steps, yes oxygenate again.

[Ozwald]

I would also go straight for the 4L (provided you're not stepping up from a slant or something).

If you do steps, decant the previous step. Never add to it. And pump in some fresh O2.