Well, this was unexpected. The picture above is just over 33 hours after my previous post. It's a little early for me to trust it, since this is after the first feeding. I'll keep feeding it until it gives a consistent rise, but this is a great sign! It's smelling deliciously sour.
Here's what it looked like before the feeding (the morning after my post, T+17hrs):
And then here's the top-down shot about 16 hours later:
Nearly a full doubling, vigorous gas production. Just incredible.
Maybe it's a mistake, but I'll keep feeding it and posting the results.
Looking good!
I've had good results using sprouted wheat flour to feed sourdough starter, just throwing that out there.
You might get even better results by putting it in the jar instead of throwing it out there.