[CliffordK (OP)]

I seem to be eating less bread as the temperature warms and I'm getting a wider variety of foods, and my sourdough is growing faster as the weather is warming. 

I've been having lots of problems with hyphae growing on top of my sourdough?  Are they a natural part of the sourdough?

I've been pouring/scraping off the top layers and using the sourdough underneath which seems to be just fine.  I then clean my container and regenerate my sourdough from my flour/water/sourdough pre-mix part of my bread dough.

So, are the hyphae a sign of contamination, or a natural part of my sourdough yeast?  It would seem that natural yeasts would likely retain the spore forming capabilities to help them spread.

[Bored chemist]

I'm not a mycologist but it sounds very dodgy to me. Also from
http://en.wikipedia.org/wiki/Saccharomyces

"They are unicellular, globose, and ellipsoid to elongate in shape. Multilateral (multipolar) budding is typical. Pseudohyphae, if present, are rudimentary. Hyphae are absent."

If I were you, I'd get a new starter culture.

[CliffordK (OP)]

I'm not a mycologist but it sounds very dodgy to me. Also from
http://en.wikipedia.org/wiki/Saccharomyces
...
If I were you, I'd get a new starter culture.

Sourdough is easy enough to start...  no commercial culture needed.
Mix flour + water.
Wait...
Take part of it, and mix in more flour and water.
I think the yeast starts fairly quickly, but it may take a week or two to get a nice flavor.

Thus, while one can start over, it is easiest to keep one's old culture.

Here is a list of organisms commonly found in sourdough.

These include candida milleri (humilis) and candida krusei.  I think most of the yeasts/fungi in the genus candida either form hyphae or pseudohyphae. 

I'm seeing notes that  lactobacillus actively inhibits many molds including penicillium molds.

Perhaps the next time I get hyphae (or I could try to force them), I should try to better identify the fungus, and see if I can go from hyphae back to bread yeast.

Anyway, for now, I'm regenerating my sourdough starter from my "premix", and cleaning the container more frequently.  Perhaps I'll try refrigerating it, or drying a few samples.

[Bored chemist]

One other thought that occurs to me is that there are plenty of food grade products that will inhibit most microorganisms but which have relatively little effect on saccharomyces and (at least some strains of)  lactobacillus.

It might be interesting to try culturing the flour with beer or wine rather than water in the first place.

[CliffordK (OP)]

It might be an interesting experiment.  I don't really want to kill off the sourdough part, but perhaps ethanol could be used to help purify baker's yeast.  However, I don't think I have any ethanol in the house, at least that hasn't already been denatured. 

Some organisms "like" ethanol.  I wonder if adding ethanol to sourdough would select for acetobacter.  Lactobacillus may also chew up some of the ethanol. 

One might end up with some interesting flavors.