Leavening with Sourdough starter only

Imho I'd use a king arthur recipe and use the baking soda as well.  I personally wouldn't have a problem using it.  

https://www.kingarthurflour.com/recipes/classic-sourdough-waffles-or-pancakes-recipe

Sourdough starter leavening and baking soda leavening are two different things.

Sourdough starters and commercial yeasts produce CO2 in a fermentation process, which means it's the living creatures (fungus and bacterias) metabolizing and breathing, thus produce gas to make the dough light and fluffy. 

Baking soda and baking powder produce CO2 in a purely chemical reaction. It's the NaHCO3 in the powder that gets decomposed when heated. The chemical equation is 2NaHCO3 ==== Na2CO3 + H2O + CO2 (gas)

Okay, that might be too much of biology and chemistry. Here is the real reason: waffles and pancakes have a higher oil and sugar content in the batter, which will largely decrease the activity of the yasties in the sourdough starter, while chemical leavenings aren't affected at all. Another reason is that since the batter is very thin and there's no folding to develop gluten strands, it wouldn't be able to trap air and make the end product light and fluffy. 

I personally don't have a problem with using chemical leavening in my pancakes, but if you don't feel like using them, maybe try a small batch with less oil (or butter) and less sugar and see how it turns out. Good luck with your 100% natural pancakes and waffles! 

is to use the same amount of soda and baking powder in sourdough pancakes as I do in pancakes without sourdough. I find that the acids produced by the starter work very much like the acids in buttermilk; they react with the leaveners to produce very light pancakes.  

One cautionary note: use a mixing bowl that has enough volume for the batter to at least double after adding the leaveners.  Once they are stirred in, the batter begins to expand dramatically. 

Paul

Here is a link to a recipe at King Arthur:

https://www.kingarthurflour.com/recipes/classic-sourdough-waffles-or-pancakes-recipe

This is exactly the recipe used by my godfather, who began mining gold in the Sierra around the turn of the Twentieth Century.  He kept a little crock of starter on a shelf in his kitchen.

The notable thing is that the bulk of the batter is made from a sponge that has been left out overnight at room temperature.  This means that all the starch has been used up by morning.  So, is this good?  Well, pancakes make me sleepy, and I have read that it is the starch in them that causes that, but in these there is no starch — the yeast ate it all.  Product: non-sleepy pancakes.

But are they any good?  Well, they far exceed any other pancakes I have ever eaten in my whole life, which has been longer than I care to tell.