yeast starter is it completed?

[Frostyp]

making my first yeast starter,how do i know when its completed and ready too step up the one ive got going at the minute has been running on my stirplate for twenty four hours now, is that long enough? im still seeing bubbles rising, do i leave it constantly spinning until i see no bubbles rising? or is there a time preference?

 

[Good Ed]

You'll know when it's finished because there will be no more bubbles from fermentation. If you are then going to step up, you should put somewhere cool for 24 hours to let the yeast settle out, and then pour off the spent wort before adding it to some fresh wort for the next stage.