Help - sourdough in San Francisco?

I am going to be in San Francisco for work in a couple of months time, and I expect to have a day free when I am there.  I would love to have any suggestions about sourdough in SF - where to go, what to try, etc, etc.  I want to put together a day's sourdough tour for myself!

Many thanks for any suggestions!



And if you travel a little bit north of San Francisco you can check out

That should give you a good selection.

Thanks LD,  will try these out - and report back