Something in the Air

I've just made up a sourdough starter based on the simple concept of flour + water = starter. I'm hoping to harness whatever wild strains of yeast are floating in the Pittsburgh air and in the flour I chose.

1/3 c white flour
1/3 c buckwheat flour
2/3 c water

Just plain white flour seemed boring, and I have some buckwheat kicking around in the cabinet. The batter's slightly gooey and takes up about 1 cup of volume. The color is brownish gray and smells like flour. I have it sitting on top of my furnace to stay warm; we'll see what happens.