Crispy Sourdough Waffles

wholemeal flour

dark rye flour (or more wholemeal flour)

fine cornmeal (the stuff which is still gritty but not super coarse)

sourdough starter* ((100% hydration) (see notes))

sugar (, honey or maple syrup)

water (yep, I weigh it)

egg

olive oil or melted butter ((plus more oil for the waffle iron))

baking powder

salt

vanilla extract