I made a yeast starter about three hours ago. When I swirl the beaker I get a large amount of foam, or good yeast. When do I add it to my wort? After 24 hours, 5 hours? How do I know when is the right time to add the yeast?
I’ve read anywhere from 18-48 hours. I usually wait the full 48 hours, put it in the fridge till the yeast settles to the bottom (usually around 24-48 hours) decant off all the liquid on the top (which probably doesn’t taste good so do you really want it in your beer?). Leave just enough liquid to swirl and pour the yeast.
So for a single step starter, absolutely maximum is around 4 days. Minimum is just shy of 2 days.
If you don’t mind pouring your starter “beer” into your wort then you can remove the fridge/decanting step.
Some people like to pitch at full krausen, which would be when it really gets foaming up good. Others like to let the yeast ferment out the sugars and drop out, then they can decant off the starter beer and pitch the slurry. Its all good. 3hr is kind of short though.
I like to give my yeast starters about 48hrs. Sometimes life does not allow time to make a starter that far in advance though. I have pitched them as soon as 12 hours after making them. I probably didn’t get the full potential out of it then but even in those instances it did seem to work better than just pitching a smack pack with no starter.