Stir Plate Question

I am going to start making and using starters. I understand that stir plates will help to make more healthy yeast. So the question is how to properly use a stir plate??? After pitching the yeast into the flask do I need to turn the stir plate to make a vortex and keep it on until I am ready to pitch the yeast in the wort???

Generually speaking, you should spin the yeast until either:
1) It's at high krausen (~18 hrs or when foam is at it's highest) and you're ready to pitch the entire contents directly from the stir plate.
2) It's finished the stir plant (24-48 hrs) and been crash cooled for a day or two.

The vortex isn't as important as keeping the yeast suspended and not throwing the stirbar, but, yes, the stir plate will be running the entire time (18-48 hours).

Awsome, Thanks for the replies and information.

+1 on room temp and stir plate.

http://www.stirstarters.com/

highly recommend checking this guy out. A bit on the expensive side but it has a lifetime warranty and alot of people on here have gotten their stir plates from him. Anyone that had a question or an issue with their plate basically received brand new starters in the mail from him. he also includes a stir bar and a magnet that u keep on the outside of ur vessel that attracts the stir bar to the side and keeps it from going into ur wort when u pitch.

I always try to pitch when the yeast is actively fermenting, not after it has settled out.

For a small starter (<2L for 5.5 gallon batch) I will time my starter to pitch at high krausen (~18 hrs in) with the starter on the stir plate the whole time.

For larger starters (>2L for 5.5 gallon batch) I use a slightly more involved process in order to pitch actively fermenting yeast without pitching a huge volume of unhopped oxidized starter wort into my fermentor:

First I build up a starter with a bit less than what my target starter volume is (I use the Mr. Malty calculator). For instance if the calculator said I needed a 3.5L starter I will make a 3 liter starter.

I ferment this on the stir plate until it is done (usually around 48 hours)

Then I take it off the stir plate and cool crash it to drop the yeast out.

18-24 hours before I plan to pitch my yeast I decant off the original starter liquid and add 1L of fresh oxygenated starter wort and throw the whole thing back on the stir plate.

With this method I am able to essentially concentrate a 3.5L starter worth of yeast into 1L of active starter.

This method has worked great for me on light lagers that require huge amounts of yeast but are also very susceptible to off flavors that could potentially be introduced by a large volume of starter liquid.