Separate starters?

3 different starters are not needed. Commercial yeast is a different strain of yeast than sourdough yeast. The bacteria in sourdough give it the different flavor profile. Not everyone loves sourdough, it's not necessarily better, just different.

Jim

If you're baking that many loaves, then perhaps seperate starters would be useful to you.

I just maintain a white starter. When I need a rye, I just innoculate rye flour and water with a bit of the white starter. Ditto other starters.

The answers are connected.  Sourdough bacteria create an acidic environment by producing lactic acid.  Sourdough yeast are able to live in more acidic conditions than commercial yeast, because that is the environment to which they are adapted.  The populations of yeast and bacteria living on a particular grain are suited to that grain.  If you cultivate a starter on rye and then use it to bake rye bread, the yeast and bacteria will be living on their preferred food.  If the grains were not somewhat different, no one would use more than one type of grain.  That said, if you are cooking with blended flours then it probably makes sense to just use either the cheapest or the one that gives you the most flavorful sourdough.  If you don't want to fish around for your own culture, you can buy sourdough innoculants of various strains on the Internet.

Commercial yeast is a reliable fella that eats any starchy flour and performs predictably and quickly. He tends to fizzle out over the generations and that is a characterisitc that doesn't make him a good candidate for a long term culture.

Different yeasts found on different flours tend to perform best when added to flour for which they are adapted but they will work on other flours. A yeast cultured from AP flour is a different variety of yeast than that cultured from rye flour. Will rye cultured yeast eat AP flour and produce a loaf? Sure, but it isn't as efficient and there may be some other issues that pop up.But in the long run, it would prob work well enough. I know that when I use a AP starter in a whole wheat recipe that requires a long ferment, it may tend to go a little "off" unless I use the whole wheat culture. Same with rye.

SOmeone here on the forum uses a mixture of AP,whole wheat and rye(80%-15%-5%)? to feed his starter. Seems like it would cover all the bases once it stabilizes into a good starter and a method I've been meaning to try.

SO start with a starter for the flour you will use most often. Adapt from there.