Sugar-Free Sour Dough Starter & Bread

This is from Wholesome Sugarfree Cooking:

2 cups flour
2 cups water
1 cup cooled potato water (left over from cooking potatoes)
1 Tbs yeast

Mix well and set in warm area until done fermenting (it will separate and not more bubbles will be present)
Stir well and remove 1 cup -- then stir in 1 cup of flour and 1 cup of water. The new starter is ready to use in 3-4 days.
The sourdough flavor will improve as your starter ages.
Feed starter several times a week, always removing 1 cup then adding 1 cup flour and 1 cup water (or enough to make it soupy).
Do not refrigerate. Let it stand on the counter.

The Bread:
2 cups starter
1 cup milk
1/4 cup honey
1/4 cup butter
2 tsp salt
2 tsp soda
5-7 cups flour

Scald the milk. Stir in butter, honey and salt into milk and cool to lukewarm. Add sourdough starter. Dissolve soda in 1 Tbs warm water and stir in. Add flour until dough in able to be handled for kneading.
Let rise 3 hours. When doubled, punch down and shape into 2 loaves. Place in greased pans and rise until hump is above edges of pans.
Bake at 400 for 25-30 mins.