Alright, for dry yeast you don't need or even want a starter, but they're a must for liquid yeasts.
Pitching by simply sprinkling on top is the preferred method now. So is not aerating/oxygenating, although it shouldn't hurt if you did. I haven't seen any proof for or against yet.
If there's still a krausen, fermentation is ongoing. Don't judge by airlock activity, unless it's a really closed vessel.
Been looking for a place to jump in here.
I'm currently fermenting a sort of ESB/Amber ale thing. I used S-04 dry yeast.
1. Sprinkling on top is actually the best approach.
2. You do not need to oxygenate with dry yeast. It's been cultured and then dried and packaged in such a way that it's packed with Sterols, which are necessary to producing cell walls. To create more yeast cells the budding needs that. Normally oxygen is used (most efficiently) to do that, but with dry yeast you don't need to oxygenate.
3. I know that sounds weird. I'm still struggling with it, but it works to not oxygenate.
4. Would it hurt to oxygenate? Not really.
5. However, the beer I'm fermenting was brewed on Sunday. Pitched the dry yeast at 12:30pm. I never saw any evidence of activity via the blowoff jar before I went to bed at 11:30pm.
6. Next morning, 6:30am: bubbling. Not really vigorously, but bubbling away nonetheless. So, in less than 18 hours, I have activity.
7. I pitched at 77 degrees, let it sit there for a few hours, brought it down to 71, then 66 degrees.
8. Monday morning, dropped it to 64 degrees.
9. Today is Wednesday. OG was 1.058. I have a TILT hydrometer in there that read 1.055 (at high levels it's not quite as accurate). This morning, 6:30am, I was down to 1.024 gravity.
I need to run home and close up the fermenter now so it can self-carb. But I didn't oxygenate the wort, and it'll essentially be done by tomorrow morning--maybe even tonite.
So, no oxygenation, and I'm still getting vigorous fermentation. We'll see, later, how it tastes, but no evidence it'll be different than normal.