"Doug Essinger-Hileman" wrote:
>Actually, the local "air" is the largest determining factor, in my
>opinion. The flavor of the sourdough bread is dependent on the
>makeup of the yeasties and other beasties, and that varies from
>locale to locale. You can buy sourdough starter that is cultured and
>grown in San Francisco, and at the beginning the taste will be just
>like any sourdough you've had in SF. But if you keep the culture
>alive, it will eventually replace the SF "character" with the local one.
A commonly asked question I get at the sourdoughhome.com web
site is, "will my starter change when I move it?" with its corollary
of, "When I moved from St. Louis to Poughkeepsie, my starter changed,
what happened?"
There are more old husbands tales surrounding sourdough than almost
anything else I've been involved with, with the possible exceptions
of high-end audio and brewing.
Dr. Michael Gaenzle of the German Cereal Institute studies sourdough
starters and says he has starters that the institute has had for over
50 years that have not changed in that time.
Somehow, I can still hear someone saying, "Yeah, but my starter
doesn't taste or work the same as it did before I moved!"
There are lots of factors at play here, so it's not as simple and
straight forward a topic as you might find in a biologist's lab slants.
Before I get too far into the discussion, I'll preface my comments by
saying that all the comments apply to a healthy culture. And that
many hobbyist's cultures are on the ragged edge of death. Good
culture maintenance is very important.
Almost all cultures, whether a hobbyist culture or a professional
baker's culture are impure cultures. There are around half a dozen
yeasts and three or so lactobacillus strains that can make a viable
sourdough culture. Most of our cultures have many of these in them,
but one strain of yeast and one strain of bacteria are dominant. If
we change how we handle our cultures, we can change which strains are
dominant. And the taste and activity of the culture can change.
Sometimes this is good, sometimes it isn't.
Changes in cultures, absent changes in feeding habits, are unlikely,
for the same reason that most experienced sourdough practitioners
discount the "starter from the air" theory. If you look at the count
of yeast and bacteria in a volume of air, and compare that to the
count in a gram of flour, it's obvious the odds favor the flour being
the source of the culture. Dr. Ed Wood in his "World Sourdoughs From
Antiquity" book recounts an experiment he did for National Geographic
wherein he tried to capture an authentic Egyptian culture from the
air. He irradiated the flour so it would not have anything alive on
it. In a lower-rent fashion, a number of people in
rec.food.sourdough tried to get local cultures by pouring boiling
water over the flour to try to sterilize it. In both cases, the
experienced people went from nearly universal success at starting a
culture to a very high failure rate. This corroborates the idea that
most cultures are started from the flour, not from the air.
Similarly, the yeast and bacteria count in an active starter is much,
much higher than the count in flour. A large part of the stability
researchers, such as Dr. Gaenzle, report in cultures is because the
lactobacillus bacteria produce a number of chemicals to kill would-be
invaders. The acidity of sourdough starter is just the front line of
defense. So, it seems very unlikely that a healthy starter could be
taken over by the yeast and bacteria found in either the air or flour.
Now then, if you've been taking good care of your culture, what could
make the bread made with it taste different? Hunters prize boars
that have been feeding on acorns - it gives the meat a great taste
(or so I'm told - if you want to send me a care package, I'd love to
try some! French farmers force feed their geese special herbs and
spices to give the pate made from the livers of those geese special
tastes. Many nursing mothers report that when they eat this food or
that, their babies no longer like mom's milk. If more complex
organisms change their taste, or the taste of things they
produce, based on what they have been ingesting, is it any surprise
that yeast and bacteria would also change their taste, and the taste
of the breads they produce, based on changes to their diet?
There are regional differences in flours, even when the brand name on
the sack is the same. Different flours taste different. And it
seems that yeast and bacteria notice differences we don't.
Try converting your starter from white to whole wheat or rye flour.
There are very rapid changes to the aroma and taste of the starter,
well beyond what you'd expect from the changes in the flour.
A number of experienced sourdough bakers have said that the key to
copying another baker's bread isn't getting their sourdough starter,
it lies in finding out what kind of flour they are using.
So, if your starter changes, maybe you need to send back to friends
who didn't move and ask them for care packages of your old standby
flour. Or just get used to the flavors that the flours in your new
home produce.
All of this, to me, suggests that the theories about climate and air
causing changes in sourdough starters are just old husband's takes.
Best wishes,
Mike
Mike Avery mavery at mail dot otherwhen dot com
part time baker ICQ 16241692
networking guru AIM, yahoo and skype mavery81230
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