I have some tried and true quickbread recipes. I wonder if there is a formula (more or less) for using sourdough starter in these. Perhaps, depending on my starter's hydration, remove that amount of flour and liquid from original recipe, and then eliminate? reduce? the baking powder/soda? Does anyone have any experience with this?
Use however much mature starter you wish but reduce the flour and water accordingly depending on how much is in the starter. Then however much starter you have used will effect how quickly it takes to ferment. Things you want to consider is time and flavour. Watch the dough and not the clock.
That's about it in a nutshell.
I have used this for years. Found here on TFL. Always works extremely well. I let it sit for one hour before baking and the rise is lovely and the crumb very tender and flavorful. I use it as a base and simply substitute other things besides and with the bananas. I have used applesauce, quince paste, different nuts and dried fruits. All have worked well. You can use pears or peaches or any other cooked fruit. http://www.thefreshloaf.com/recipes/sourdoughbananabread
If you want other ideas for subbing sourdough starter into quick breads there are tons of blogs that have recipes. Almost every one of them calls for 1c sourdough starter unfed. I have not seen any that don't call for some other leavening. You need to look at the sourdough starter as an equivalent to buttermilk as far as acidity and use some baking soda to get a rise. Hope this helps your research ! https://www.google.com/search?q=sourdough+starter+quick+bread&oq=sourdough+starter+in+qui&aqs=chrome.2.69i57j0l5.8102j0j7&sourceid=chrome&ie=UT…
I have routinely just added about 1 cup of discarded starter to the already mixed dough but I'm just using it for flavor-not rising power. The acidity will provide a nice lift if you keep the baking soda or powder. Nice way to use up my discard and also a good way to stretch the recipe into another pan, usually.