Heh, OK. I misunderstood about the blending thing.
What I was trying to get at with the starter bit was to use normal wort as the initial bug capturing mechanism since wort is (I think, could be wrong) a little more resilient against bad type infections than agar would be. Since you would be scooping out the obviously yeastie bits to build up from, this does not matter for you. Then I would plate the result on agar and examine what colonies take hold, since there should be a variety of yeasts and bacteria living in the wild stuff. These guys might (again could be wrong) form separate colonies which might be identifiable, as at least different, by eye. I was thinking about getting a microscope, actually, to help with this.
So just to clarify, I wasn't meaning my comments to be a criticism for your technique, I think what you're doing will work just dandy as long as you are careful. What I had in mind was a different goal than just inoculating the wort but to give a possible idea about the number of different types of bugs and their rough identity.
Hope that's slightly clearer.