How early can I make my starter?

I was wondering if it was possible to make a starter many weeks (2-3) in advance and just keep it in a sealed container in my fridge until I need it? Should I assume I will lose some viability over that time? Any other special methods for storage I need to consider. How long should I have it at room temp before pitching?

I’ve made starters about a week ahead of time and left them in the refrigerator under the ‘spent wort’ in the flask. I siphon off the spent wort just before brewing. I’m sure there would be some loss of viability after 2 or 3 weeks storage, but you can plan your starter size with that loss in mind. I would try and avoid a storage period that long.

I never really warm mine up to room temps before pitching. 10 minutes max. I generally decant, swirl and pitch into 58-60* wort.

Per Denny, it’s okay to pitch cold yeast into wamer wort but not the other way around.