I'm new to making bread and am attempting my first sourdough. I have a pretty good looking starter and have been trying to build my levain. I started the levain build at 8 am and according to the instruction I'm following it should have been ready by 1-2pm. When I went to bed around 11:30 pm it had a lot of activity but still didn't look ready, so I let it sit overnight. When I got up it was active but had fallen from where it was the night before and wasn't passing the float test at this point.
I re-attempted it this morning and am seeing the same results; very slow rise. The only thing I noticed that I didn't follow was I used whole wheat bread flour, rather than whole wheat flour, so I'm not sure if that has any effect on it or not?
The picture above shows the starter I'm using (on the left) and the levain build at ~11 pm, 15 hrs later.
If anyone has any suggestions or input I'd love to hear it, thanks in advance!