August 10, 2010 - 7:07am
San Francisco starter
Ok, I do hope this hasn't already been asked, but I expect it might...
However, the question is this. If you have a starter, could be from SF, could be from Timbucktu, at what point after refreshment does it no longer have the right to be called, 'SF sourdough' or 'Timbucktu sourdough' starter?
If I keep adding a floour and water from anohter place on the planet, does that corrupt the original?
TIA
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My understanding is that what makes a San Fran sourdough so unique is the airborne yeast in the area. You could get a starter from there, but as you feed it, over time, it just turns into a "wherever you live" starter. This may not be so bad. San Fran sourdough is certainly unique, but that doesn't mean that it tastes any better than what you make at home.
And I been told what makes a San Fran sourdough is the wee beasties in the mountain waters that feed the area.
However, I have often read that about 2 months is as long as it takes for aquired starter to be "your" starter, in the sense that your water and airbourne yeast will have joined the party, if not completely taken over by then. I would imagine, that there are so many variables that any difinitive answer would need to be on a case by case basis.
How do I know if I have Greek Parliament starter? I live much closer to San Francisco than the Mediterranean, alas!
I started mine at home by using potato water, flour and a warm,dark boiler room closet for a few days. What kind of lab kit do I need? My teenagers are doing biology and chemistry and I homeschool, so how hard would it be to ID these little critters in my starter?
EvaGal
I've wondered about this same issue for a long time
Abstract from a science paper:
http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=135760
"Yeasts are commonly identified from either phenotype or, more recently, from diagnostic gene sequences. Methods based on phenotype include fermentation reactions on a select set of sugars and growth responses on various carbon and nitrogen sources or on other diagnostic compounds. Isolates are further characterized phenotypically from the microscopic appearance of vegetative cells as well as sexual states because this information often gives clues to the identity of a strain. Molecular methods for yeast identification include nuclear DNA reassociation as well as the more recent and faster procedure of sequencing species-specific genes or the use of oligonucleotide sequences that react to a species-specific region of genomic DNA. These so-called "molecular probes" may have a marker molecule attached or they may be used in pairs, that when employed in a PCR reaction, amplify a species-specific region of DNA. The DNA-based identifications are far more reliable than those from phenotypic tests, and much faster. Nonetheless, in the absence of facilities for molecular comparisons, satisfactory identifications can often be made from phenotype. For this reason, both phenotype-based methods, as well as molecular techniques are given in this chapter."
After reading this, I think 'Voodoo', or some other magic, would be easier for the home baker... ;-)
As a rank amateur, I'm fairly sure that, with my 'average' quality trinocular lab microscope, I could probably tell a bacterium from a fungal cell or spore...but no promises. I might still have to take a photo and send it to a lab, or spend months on the internet to be 100% sure of what I'd seen. I didn't even know, before, that yeasts HAD a 'sexual state'...identifying THAT would be beyond my humble facilities and even poorer skills
I'm still very interested in the question, but not too hopeful of an easy answer
Cheers,
copyu