Whisk, using a fork, starter and water in medium/large mixing bowl until it becomes bubbly. Add sugar and salt. Batter should taste ever so slightly salty. Whisk again, until it becomes bubbly.
Slowly add flour to wet mixture. Once mixture becomes a mostly solid mass, switch to mixing/kneading with hands. Keep adding flour until the mixture is almost dry and springy.
Let sit in bowl with loose cover (I use a cutting board or baking sheet), in a warm location (70 degrees is ideal. The warmer it is, the faster it will rise. Too cold, it won't rise), for about 24 hours.
Once dough has roughly doubled in size it is ready to bake. Set oven to 350 degrees. Transfer dough to a buttered/oiled baking dish. Score dough with sharp knife (make two to three slices part way through, about 1/4 inch deep). Bake for about 45 minutes or until knife comes out clean.
same recipe as above except...
substitute: 1/2 cup sugar
add: 1/2 raisins
add these ingredients when adding salt and continue as stated above.