Starters: technical points

I've started making more starters because I'm beginning to use more liquid yeast. I have a stir plate on order and I usually make a 2l starter in a 4l flask. I chill overnight and decant the liquid because I don't want 2l of off-flavor liquid in my beer.

Pitching temp: Assuming it's safe for the yeast, does it matter that much? I don't have a wort chiller for my flask, so it takes a while to cool, even in an ice bath. Is pitching at 85-90 bad?

Fermentation temp: I usually ferment at room temp (75ish) rather than in my fermentation chest freezer (65 or less). I figure the starter finishes quicker and I end up with more yeasties.

Aeration/oxygenation: I have been oxygenating my starter, but will I still need to when I get a stirplate?

How long: How many days before brewing do you make your starter? How long do you cold crash it before pitching? So far, I've made the starters 3 days ahead of time and chilled overnight (12-18 hrs)

I predict 45 replies and 63 different opinions Here's what I do:

For ales I build the starter 4-5 days before brewing and chill 1-2 days.

For lagers, I start 7-10 days before brewing, build the starter up in 1 or 2l steps to the size I want and chill 2-3 days - the lager yeast seems to need more time to settle down.

I am using a stirplate. I usually get the starter down to 70F before pitching. My stirplate is in my basement at 60-75F depending on the season.

-Joe

I think that MB Raines, Ph.D. - Guide to Yeast Culturing for Homebrewers - Maltose Falcons Home Brewing Society (Los Angeles Homebrewing) should answer your questions. I found it very useful.

-a.