Yeast starter question

For some reason I can’t figure this out in my head. If I need a 1 liter or 2 liter starter do I make a wort or either 1 or 2 liters and just pitch the single yeast packet in? And with that much room/food the one yeast packet will grow to be a 1 or 2 liter starter? I am sure this is simple, buy my brain farting is continuous on this subject. Thanks.

The starter size will determine how much growth you will have from 1 smack pack. 1 pack in 1L of 1.040 wort will give you 50% growth (150 billion cells). In a 2L starter you can assume 100% growth or 200B cells. If you use a stir plate, you can expect twice as much growth.

Even with the same amount of sugar for them to consume? All other things being equal? Is this just because of the aeration?

Aeration and constant contact with the sugar.

The constant aeration makes sure that the yeast is always reproducing. Without the stirplate, they spend more of their time producing ethanol.

If you don’t have a stir plate, your better off doing intermittent shaking over just a simple starter. Or, just build yourself a stirplate. Its pretty easy to do.

I’ll second building a stir plate. I just finished mine and ran into no problems really. There are directions in the DIY forum section. This was the first electrical appliance I’ve ever done and it was super easy. That bragging done it will probably cause an electrical fire now…