Whole wheat sour dough starter

When building and maintaining a starter, its good to primarily use the flour in the starter that you plan on using in the bread. At the bakery I work at, we have a few different starters for the various breads we make. You could really make a starter out of any flour, really, especially if you live in an environment with particularly high yeast content in the air.

It could be because whole wheat flour tends to be a little more expensive and a little less versatile than white flour. They know that most people can keep white flour for their starter and also use it for other things, which makes it more likely that they'll use the recipe. While whole wheat flour is definitely quicker to go rancid than white flour....if you use the starter often, it shouldn't. I use half and half, and I love the complexity of the flavor.

My understanding is that starting it with part whole wheat or rye helps to get it going because of the active nutrients. Then you switch to bread or AP flour for stability. If you want to make a partial whole wheat bread, you use the combination of flours in your bread recipe to do that. The flour in the starter is a relatively small amount of the overall flours in the recipe.

According to King Arthur flour, you can feed it with whole wheat but there is an increased risk of attracting unfriendly bacteria and spoiling your batch of starter.
http://www.kingarthurflour.com/guides/sourdough/questions.html

Chad Robertson of Tartine Bakery continues to use half bread flour and whole wheat during development of the starter.

http://www.marthastewart.com/907240/chad-robertsons-tartine-country-bread