The night before you want your waffles, pull out a cup or so of sourdough starter from your fridge.
Put the sourdough starter in a large glass (or plastic) bowl.
Add the flour and water and stir it into a smooth batter. Then cover the bowl with plastic wrap and let it sit in a warm place overnight.
My neighbor will sometimes put the bowl in an oven with the light on to keep it warm during our long, cold Alaska nights.
Batter
Pull about 2 cups of fed sourdough starter from the large bowl and put it in another large bowl. Put the remaining starter in a plastic container and store it in the fridge. This will be the starter for future recipes.
Add the eggs to the large bowl with the 2 cups of fed sourdough starter and mix lightly.
Add the sugar, oil, salt, and baking soda and mix thoroughly.
Plug in your waffle iron and let the batter sit while it heats up.
Spray the heated waffle iron with non-stick cooking spray.
Ladle the batter onto the waffle iron (about 1/3 to 1/2 cup per waffle square depending on the griddle. Cook the waffles until golden and crisp. Serve immediately.
If you have leftovers, cool them on a wire rack, the put them in zip lock bags and freeze them. You can toast them for an easy breakfast on another day.