Slice raw potatoes thinly into a large pyrex or ceramic bowl ( non reactive ).
Add by sprinkling on the cornmeal, sugar,salt and pour over the boiling water.
Wrap the bowl tightly with a heavy towel and cover the towel with a foil wrap.
Place in a constant warm place overnight such as a radiator or on a low heat warming tray. Set the tray to 90 degrees or a warmth that is comfortable when touched but not to hot to touch. Then place a larger towel over the entire covered bowl.
I find that 12 to 15 hours is a good time limit to produce the foamy starter.
NOTE: If the next morning the starter isnt foamy or doesnt smell strong, then do not continue with the recipe. You must have the foam and the smell!
Now in a separate bowl, mix together the warm milk, (even skim is fine ), warm water, baking soda, salt and melted shortening or oil.
Drain the potato mixture in a colander saving the starter liquid and mixing with the milk & water mixture. Stir in enough flour ( I use
bread flour) to make smooth dough.
Knead until smooth and elastic as you would for yeast dough, about 8 minutes or so, adding more flour as needed to prevent stickiness. Divide the kneaded dough into 6, greased 1 pound small loaf (8 x 4) pans or 4, 9x3 loaf pans.
Dough should fill pan 1/3 full. Let the breads rise in a consistent warm place covered ( again use a 90 degree warm warming tray) until breads are almost double and risen almost to tops of pans.
( About 1 1/2 to 2 hours).
Bake in a 400-degree oven for 30 minutes or golden.
Remove to racks to cool. Brush tops of loaves with melted butter. The characteristic strong odor you smell as the breads are baking will not overly manifest itself in the flavor of the bread. The bread has a nice grain and texture and pleasant taste. Great toasted. Freezes well.