do all sourdough starter cultures become the same?

[cornicione54]

Okay fair enough.  In the 2 years that I have been frequenting this board daily, I do not recall anyone posting that all their starters have developed the same flavors.  

Chau, fwiw you might find Brian Spangler's experiences/observations interesting in this thread:
http://www.pizzamaking.com/forum/index.php/topic,11634.msg123514.html#msg123514

[Jackie Tran]

There is hardly a such thing as a "captured culture"

Your so called 'captured wild culture' comes from the flour itself.  Not the air.  You never captured anything.  This "wild yeast" was already present within the flour.  Another poster has tried to make this point.

It is in for this reason, at least in part, that if you want to change the way a starter tastes just change what you feed it and how much it gets fed.  Give me any starter, no matter how stable you think it is, and I can ruin it with voluminous bags of generic flour over the course of a few weeks.  It's actually not that difficult.

You aren't by anychance referring to a young versus a mature starter here are you?  Because if you are, while a young starter (one that is fed more flour relative to the seed amount and has much less residual acids) will have a less acidic and different taste than a mature starter (one that is fed less flour relative to the starter amount and has more residual acids), it is essentially the same starter and same flavor profile.  The taste will differ in strength and degree of acidity and can mask light sweetness from the flour breaking down, but is for the most part the same flavor.  

[Jackie Tran]

Chau, fwiw you might find Brian Spangler's experiences/observations interesting in this thread:
http://www.pizzamaking.com/forum/index.php/topic,11634.msg123514.html#msg123514

Thank you Cornicione,  I do recall now seeing that post although I just don't agree.  My experiences are very different.  But I will say that I have not feed my starters with rye.  I have tried feeding them briefly with 1/2 flour and 1/2 whole wheat which gives them a wheaty flavor, but I can tell it's the same starter.  When I stopped feeding with the WW blend and go back to plain ol' AP flour, the wheatiness goes away and I get the same flavors as always.  Again, I can't see inactive or dormant yeast taking off especially when there is a bazillion active yeast cells feeding and proliferating at a fast pace. 

[David Deas]

I do not argue with observations.  I simply explain them.  The fact of the matter is that you have people out there claiming *both* scenarios have happened to them depending on the particular person.  I do not ignore the opposite experience simply because it has not been mine.

Okay fair enough.  In the 2 years that I have been frequenting this board daily, I do not recall anyone posting that all their starters have developed the same flavors.  But I do realize there are other forums besides this that I don't frequent.  I should also note that I am not at all strict in my regimen to keep my starters unique and separate.  I feed them at the same time, side by side, often times using the same stir but rinsing and wiping the stir inbetween and have still manage to keep separate starters.  One of my starters when active is sweet as if it has sugar in it, while another is fairly acidic without sweetness.   I also have several others that are mildly acidic with distinct flavor profiles.  And they all seemingly differ slightly in leavening power as well.  

My experience is has been that I can change a starter by changing what I feed it and how much I feed it.

How has the starter changed?  Would you say it is a completely different starter?  A totally different flavor profile?  And does it stay different or would it revert back if you were to feed it it's normal flour again?  So the starter is like a whole new starter than from what you started with simply by feeding it a different brand or type of flour?  Do you think the difference in flavor is mainly due to the different flour used or are you convinced that new yeast from the new flour has taken hold?

Chau

For the most part a starter will revert back to what it was before if you feed it what you fed it before.  By changing the feedstock or the temperature I can change the ratios of acetic acid to lactic acid produced, for instance.  That can make it *seem* like its a totally different starter.  I can do all sorts of stuff.  It isn't that I have physically changed the culture much though.  I mean, you *can* eventually but that's not what's going on here over the short term.

[cornicione54]

  Again, I can't see inactive or dormant yeast taking off especially when there is a bazillion active yeast cells feeding and proliferating at a fast pace. 

Yes - in that regard I tend to agree. Only exceptions I can think of might be a particularly virile yeast strain that could metabolise maltose, thrive in acidic environment and present in significant numbers in the flour...or perhaps switching the conditions so radically that the current culture effectively dies and you are effectively starting from scratch.

[David Deas]

You aren't by anychance referring to a young versus a mature starter here are you?  Because if you are, while a young starter (one that is fed more flour relative to the seed amount and has much less residual acids) will have a less acidic and different taste than a mature starter (one that is fed less flour relative to the starter amount and has more residual acids), it is essentially the same starter and same flavor profile.  The taste will differ in strength and degree of acidity and can mask light sweetness from the flour breaking down, but is for the most part the same flavor.  

No.  There was post #19 you may have missed at the bottom of page 1.

If you change flours, you should see a change in the long term.

[Jackie Tran]

No.  There was post #19 you may have missed at the bottom of page 1.

If you change flours, you should see a change in the long term.

Okay I did miss that one and nice post btw.  Your response in reply #19 I will happily accept.  Let me just refocus this discussion though.  The main question here is if local dormant yeasts can overtake an existing and actively replicating culture over time (2 weeks according to Brian Spangler).  Possible?  Sure anything is possible but highly unlikely.  

  

[JimmyG]

I am going to have to agree with Chau on this one.  Once bacterial colonization is established, the flora remains stable over time, as long as regular feeding practices persist (Meroth et al, 2003). While other bacteria may occupy the starter, it would appear that they never grow to any significant degree.  Moreover, aggressive bacterial strains will only takeover if the starter becomes neglected over time (Meroth et al, 2003), i.e. leaving out your starter for two weeks with out feeding it. This may in part explain Brian Spangler's observations with his particular culture.  

Meroth C, Walter J, Hertel C, Brandt M, and Hammes W. (2003). Monitoring the Bacterial Population Dynamics in Sourdough Fermentation Processes by Using PCR-Denaturing Gradient Gel Electrophoresis. Applied Environmental Microbiology 69(1): 475–482.
This article is open access (meaning anyone can read it without subscription to the journal) and can be viewed here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC152404/

[JimmyG]

Regarding yeast population dynamics in sourdough starters, here is an article written by the same authors who essentially conducted the same experiment only with yeast. I have not had time this morning to review this article, but it is open access as well and can be viewed here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC309968/?tool=pubmed

[David Deas]

Okay I did miss that one and nice post btw.  Your response in reply #19 I will happily accept.  Let me just refocus this discussion though.  The main question here is if local dormant yeasts can overtake an existing and actively replicating culture over time (2 weeks according to Brian Spangler).  Possible?  Sure anything is possible but highly unlikely.  

  

Flour yeast can't take over your starter under normal routine circumstances.  They can be a factor.  But how big of a factor depends on circumstances.  I can only construct maybe a couple of scenarios where some sort of *takeover* might happen.

I can explain Brian's results.  But a takeover need not necessarily be at the heart of it depending on what he was doing.

[Jackie Tran]

Flour yeast can't take over your starter under normal routine circumstances.  They can be a factor.  But how big of a factor depends on circumstances.  I can only construct maybe a couple of scenarios where some sort of *takeover* might happen.

I can explain Brian's results.  But a takeover need not necessarily be at the heart of it depending on what he was doing.

I would love to hear your theory on this David, b/c Brian's post is pretty clear....

One thing to keep in mind about sourdough cultures...

They all adapt to your available yeast strains and bacteria after about two weeks and no longer have many of the properties of the propagated strain that you purchase. After 2 weeks you have a sourdough culture that you could have made yourself.

So in other words, after a 2 week period, ALL starters will adapt to local yeasts and be a (drastically or completely) different starter than what you originally started out with.  That is the starter will have different properties.  I am assuming that he is referring to the flavor profile and leavening power.
 
Am I misinterpreting or misunderstanding anything here?  So whether you have 2 starters or 200, ALL will become the same starter if fed with the same local flour within 2 weeks because the local strain(s) will have taken over. This either is true or it is false.  It either happens or it does not.  And as far as my senses tell me, it has yet to happen in my kitchen.

[Bill/SFNM]

Am I misinterpreting or misunderstanding anything here?  So whether you have 2 starters or 200, ALL will become the same starter if fed with the same local flour within 2 weeks because the local strain(s) will have taken over. This either is true or it is false.  It either happens or it does not.  And as far as my senses tell me, it has yet to happen in my kitchen.

Starter cultures you capture may or may not have the strength to resist contamination. It's like a box of chocolates... However, ones like you purchase from sourdo.com that have been in use for a few hundred years, that have been selected for excellent flavor and leavening, if properly cared for, are able to resist contamination in normal use. Let me tell you that the Russian starter I have is so prolific in flour and water, I find it hard to believe that any local invaders could ever establish a toehold.


 

[Jackie Tran]

Exactly my thoughts.  One can probably contaminate any starter if one really wanted to or worked at it.  BUT does it happen on a routine basis as some believe? 

This also begs the question that if it does happen, how in the world would anyone be able to maintain a business of selling starters such as sourdo.com.  What would be the point of purchasing a starter? 

I have made several starters from scratch presumably propagating yeast that is uniquely local to the area or the flour that I use, and even a simpleton such as myself will tell you it tastes completely different from my other starters that I have received from other members.

[Bill/SFNM]

I'm with you, Chau. I've been doing this wild starter thing for over 20 years. The "single local domination" theory is just a myth. That there is little difference between starters is also one of those myths. You know wine is just fermented grape juice but boy can those wine enthusiasts wax pedantic about minuscule differences in every factor you can imagine having a massive impact on the tongue and nose. Maybe wild starters in breads and pizzas aren't as varied as wines - the time frame from start to ingestion is considerable shorter. But the differences between cultures are still very significant.

[JimmyG]

Chau and Bill,
Both of your observations are completely consistent with the scientific literature regarding yeast or bacterial propagation in sour doughs starters. As long as you practice good feeding and storage habits with your starters, there should not be any issues regarding local flora takeover.

[Jackie Tran]

Thank you for the links JimmyG.  I will read them over tonight.

[TXCraig1]

The math - even with generous assumptions for the invading flora - suggests it is highly unlikely that an established healthy culture could be dominated under normal circumstances.

Model it if you don't believe me.

CL

[dmcavanagh]

 I usually don't like to get into discussions about sourdough, too many conflicting opinions and information or more likely misinformation. My question to those who believe a culture remains stable, can you still make genuine San Francisco sourdough with your starter once you leave San Francisco? San Francisco bakers say NO! So do a lot of sourdough "experts". 

[Jackie Tran]

I usually don't like to get into discussions about sourdough, too many conflicting opinions and information or more likely misinformation. My question to those who believe a culture remains stable, can you still make genuine San Francisco sourdough with your starter once you leave San Francisco? San Francisco bakers say NO! So do a lot of sourdough "experts".  

DMC, I don't know enough sourdough science to say yeah or nay.  Common sense tells me yes it's possible.  I agree with you there is a lot of misinformation out there among experts and non experts.  As far as making SF SD outside of San Fran, if not then why not?  If you have any credible information one way or the other, by all means post it up.  

Also, have you or do you use starters? If so, did you note if the flavor profile changed over time?

[TXCraig1]

I usually don't like to get into discussions about sourdough, too many conflicting opinions and information or more likely misinformation. My question to those who believe a culture remains stable, can you still make genuine San Francisco sourdough with your starter once you leave San Francisco? San Francisco bakers say NO! So do a lot of sourdough "experts". 

Yes, I can do it anytime I feel like. I have had plenty of SF bread in SF. I know what it is supposed to taste like.