Whisk all ingredients in a separate bowl.
Add this mixture to your sourdough levain mixture all at once.
Stir thoroughly: you don't want streaks of unmixed sourdough in your batter. The batter will start to swell from the baking soda acting with the kefir and sourdough.
Pre-heat your waffle iron and cook according to your manufacturers instructions. My waffles take about 3 to 5 minutes.