1/2 tsp. dry yeast
1 1/2 c. lukewarm water
2 c. flour

Soften yeast in water; add flour, stir to mix. Put in glass container with loose lid. Never use metal container for sour dough. Be sure it is a large container as dough expands. Let set at room temperature for 3 days, stirring 1 or 2 times a day. The starter will work and have a sour odor. After starter has soured, it can be stored in refrigerator until used.