1. The night before prepping your dough, feed your sourdough starter equal parts flour and water, about 200g each. Leave in a warm place, such as an oven with the light on.
2. Check sourdough starter before baking using the water test method. The starter should be nice and bubbly and will float on top of the water. 
3. Mix the sourdough starter and water in the bowl of a stand-mixer with a dough hook attachment. Sprinkle yeast on top and let bloom for 10 minutes. 
4. Add the bread flour and mix on low until dough fully comes together. 
5. Turn mixer to medium to activate gluten and mix for about 5 minutes.
6. Turn mixer to high and mix for an additional 1 minute.
7. Let rest for 15 minutes. 
8. Add in walnuts, cranberries, and salt, mixing on low until fully incorporated.
9. Bulk proof the bread in a large, greased bowl, cover with plastic wrap for 90 minutes at room temperature.
10. Divide dough into 6 even pieces, about 320g each. Roll into logs like baguettes by pinching any seams together.
11. Grease loaf pans and punch dough down flat into the pans.
12. Cover in plastic wrap and place in the fridge for up to 16 hours or overnight to ferment and develop that delicious, tangy sourdough flavor. If you don't like your sourdough quite so sharp, reduce the bulk fermentation time to down to no less than 4 hours. 
13. When bulk fermentation is complete, preheat your oven to 450F. Place a metal sheet pan on the right side of the bottom rack of the oven. 
14. Remove your loaves from the fridge and score your loves down the middle. Place on the left bottom rack.
15. Pour a cup of ice into the hot sheet pan to create steam while your bread bakes.
16. Bake for 20 minutes.
17. Remove bread from pan and place onto a sheetpan with a wire rack.
18. Reduce oven temperature to 400F and bake for an additionl 10 minutes or until the bread is golden brown.
19. Cool for 20 minutes before slicing. 

Serving suggestions: Whip together softened butter, a touch of honey, and flakey sea salt to spread or dip in.