This is a very moist sponge or starter for delicious wonderful breads.
4 cups flour
4 cups cool water
1/4 tsp. yeast
Combine all ingredients together in a large bowl. Beat or whisk together until well mixed and smooth, about 1 minute.
Cover the bowl with plastic wrap, and let stand at room temperature until frothy and bubbly, about 3 to 5 hours.
Make sure the poolish is tightly covered, and refrigerate overnight.
You can use for baking (or freeze any extra for future baking) the next day.