wrote:
I've been feeding my Carl's starter with King Arthur bread flour.
After a few learning experiences related to temperature, it's been
doing quite well and producing good sourdough loaves.

I'm curious about the effect that changing to a different grain would
have on the performance and taste of the starter. I have access to
wheat, rye, oat and rice flour. Any experience out there on this
subject ?


It will change - results may vary.

Mineral content, taste of grain, grain properties.

Btw. oats are not a bread grain, nor is rice.

If you cook something with barley and do the same thing with wheat
berries - do you expect it to be the same?

IMO, sourdough is mainly an experience and no words - printed or spoken
can substitute that experience.

In a way, it seems you are asking here for the experience.

There is so much to sourdough fermentation - injera, pannetoni cake,
pumpernickel, full grain sourdough pan cakes, all are using similar
organisms to come to vastly different results.

I can only encourage you to experiment, discover and enjoy.

Sam