Fact or Fiction

The yeast comes from the flour.  Specifically, it hitches a ride on the grain before it's ground.

Whether or not the yeast population from an imported started will disappear over time, though, I don't know.  During each feeding, you'll innoculate the starter with yeast from an outside source.  But, at the same time, the original yeast continue to multiply... maybe you just end up with some kind of twisted franken-starter? :)

There is much controversy around this topic.

I recently attended a seminar with a number of folks who are well qualified artisan bakers and they expounded on this topic.

They maintain that eventually, under normal bakery/home conditions a starter will take on the character of the flour that it is fed.  They claim that starters started with "grapes pressed by virgins" can only maintain that special character if the starter is constantly fed with those very same grapes.  They base this on the theory that whatever yeast/bacteria will become part of the stable starter are those that can compete best in the environment and those that compete best are the yeasts that are in the flour that is used to feed the culture.   They also base this on somewhat subjective tests that they have run.  They also claim that a well matured starter (3 or 4 weeks of age) is no better or worse than a "100 year old starter carried by prospectors over the Rockies."

Others disagree. They are convinced that by careful maintenance they can keep the character of the original starter. Others will argue that their 100 year old starter has gotten a special depth and flavor from its maturity and high altitude trip and that it makes a particularly delicious bread.

I will not disagree with either camp.

I will say that I have found how a starter is maintained can have profound effects on bread taste and quality, so that is where I put my effort rather than searching for that one special starter from around that world that will produce a special bread. I'd hate to lose my starter because of the bother of bringing it back and I'd feel that I had been somehow neglectful to kill the thing, but I'm convinced I could.  My opinon only - not a universal truth.

I know this resolves nothing, but I hope it helps.

I must concur with proth5.  Unless my goal is to produce some extraordinary prize winning loaf of bread that shakes the heavens I'm not spending a lot of time trying to create or locate the "perfect" starter that I cannot feed with its original flour formula.  Even flour charcateristics change, sometimes dramatically, from one processed bath to another because of small differences in their environment throughout the milling stages, etc.

IMO, it's  much to do about nothing.  My now three year old pineapple starter produces a wonderfully full flavored bread and I can manipulate its flavor by feeding portions of it with difference types of flour.  That's enough for my needs.

Any time I have been given a piece of culture (one, attributed with mythical qualities, was said to be over 100 years old), I have found that on my usual regimen of feedings and warm room temperature, within two or three days it produces a pain au levain that tastes exactly like my usual one.

From The Art of Eating 2009, number 83.

A few years ago, when I decided to create a sourdough culture, I, too, wanted to capture all those wild yeast supposedly floating about.  So I mixed flour and water and put the container outdoors (covered with a piece of cheesecloth) on my deck.

When I checked several hours later, indeed I had captured wild beasties - but they all had wings.

Dumped it, did another mix of flour  and water, kept it in a covered jar, and my sourdough has been serving me well for over three years.

Proth5 and FNW have given good advice.

In addition the the points above, sour is more controlled by the length of time the sour builds, the fermentation temperature, the percentage used in the recipe, and the overall fermentation time (3 hours all the way to three stages built over several days?). 

German ryes are very sour and usually use a more liquid starter which ferments faster than a thick starter.  Rye ferments faster than white flour.  With so many variables seek out the type of recipes you are trying to emulate. 

Boudin Bakery in San Fran makes wonderful sourdoughs - there are you tube "bakery tour" videos that show a  chilled final fermentation of 14 hours - which will add more tang then a quick rise.  5% or 25% at the start of your recipe.  Two to three day builds will give a very strong tang - See Hamelman's Bread Book.  Dan Leader's "Local Breads" book is worth picking up too.

I started and maintain mine with pure fresh ground organic rye from Minnesota and keep a 1:1 ratio by weight of flour and water.  It is very vigorous (largely due to removing from fridge 5 hours prior or even overnight, and building in two stages 3 hours apart to 15% of a given recipe.  At that point with 15% of your recipe being very active it surely will carry forward vigorously. 

IMHO no need for several starter types.  Good luck!

Don't any of you know, with all your collective knowledge of bread, that wild yeast are carried on the wings of fairies ?

The fairies are very loyal. They follow the scent of a culture they've started on it's travels around the planet for centuries and continue to seed it with fresh wild yeast. Thereby assuring that each culture has it's own unique taste and remains a family heirloom.

Of course in the 25 years that I worked as a professional baker I never met a fairy that could take the heat in the kitchen so we couldn't rely on them. We always just let a culture mature for 3 weeks before using it. Flour, water, citric acid and or fruit juice. Orange or apple worked every time. Never bothered with pineapple. Thousands upon thousands of ferments all rose to varying heights. The success and flavor more determined by the bench time, bulk ferment and skill of the hands than any other component.