Adapted from http://www.kingarthurflour.com/
2 cups warm water
1 tablespoon honey
1 package active dry yeast
1-1/2 cups whole wheat flour
1/2 cup all purpose flour
Measure the water in a 8 cup liquid measure. Stir in honey. Add in yeast. Stir to dissolve. Slowly add in flour.
Cover with cheesecloth and place in a warm area.
Stir once daily for five days. After the fifth day refrigerate until ready to use.
Don't use a smaller measuring cup. I put it in a 4 cup measuring cup at first. It bubbled up into the cheesecloth in about 15 minutes.
Picture below: Yeast Day 1