I bake weekly using a levain. I preserve about 25g from the levain in the refrigerator as my starter. There seem to be two choices for how to do this:

1. After feeding the old starter to begin the levain ferment.

2. After the levain has fermented.

So I conducted an experiment. I now have two 25g starters in my refrigerator. The first is fed but not fermented. The second is fed and fermented.

Visually these starters are quite different. (1) is ‘ bready’ and full of bubbles. (2) is soupy and no visible bubbles, but on close examination there are fine bubbles in it.

Baking the same recipe for each I get approximately identical results.

As far as I can tell it makes no difference which method I use.