Overnight sourdough waffles

I love these waffles.  

Blend together: 

100 g sourdough starter 
460 g buttermilk/kefir/yogurt/milk 
100 g melted butter 
250 g spelt flour 

let sit overnight or until lunchtime. 

stir in 1/2 tsp bicarb 

separate two eggs. beat yolks together and add to batter.  beat whites until firm and fold in. 

cook on waffle iron or griddle.