Author Topic: do all sourdough starter cultures become the same?  (Read 22823 times)

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Offline TXCraig1

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Re: do all sourdough starter cultures become the same?
« Reply #100 on: March 25, 2012, 08:12:31 PM »
I don't understand why you seem to bound on pretending I've disrespected you.  You're the one who marched in here talking about what was absurd.  Is it disrespectful if I don't bend down and kiss your "right" rear end?

With due respect to you, you should read the thread a little more thoroughly before replying.  I don't feel like its that long. 

I'll give you the benefit of the doubt no disrespect was intended, but that is how it was perceived at the time.

In the contest of the orginal question, suggesting that it is plausible if you first torture the culture into submission is absurd.

[/quote]
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Offline TXCraig1

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Re: do all sourdough starter cultures become the same?
« Reply #101 on: March 25, 2012, 08:13:15 PM »
You're stil talking about a takeover, period.  I've already answered where such a "takeover" might likely come from.

You said I'm stuck on that. I'm simply asking where else it might come from?
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Offline David Deas

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Re: do all sourdough starter cultures become the same?
« Reply #102 on: March 25, 2012, 08:23:13 PM »
I'll give you the benefit of the doubt no disrespect was intended, but that is how it was perceived at the time.

In the contest of the orginal question, suggesting that it is plausible if you first torture the culture into submission is absurd.



The original question was answered within the first few posts by members who have experienced something different, which automatically refuted the notion of "all starters" behaving a certain way.  

From there it was concluded that mistreatment must be the issue because these sorts of reports were coming primarily from people who are just getting acclaimated with their starters.  So I was trying to draw up scenarios wherein the starter might be damaged beyond repair.  I do not agree that posts not directly addressing the original question are absurd.  I do not agree that leaving a stater out for long periods is uncommon amongst novices, and comparable to intentionally destroying the culture with bleach.  If you thought otherwise it would have been enough to plainly state so.

Online Pete-zza

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Re: do all sourdough starter cultures become the same?
« Reply #103 on: March 25, 2012, 08:26:59 PM »
Guys,

One of my duties as a Moderator--my least favorite one--is to try to keep peace and harmony on the forum. Please take a deep breath and try to avoid anything that might be taken personally by the other.

Thanks.

Peter

Offline TXCraig1

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Re: do all sourdough starter cultures become the same?
« Reply #104 on: March 25, 2012, 09:06:20 PM »
David, I never meant this thing to turn into a fight. I apologize if I came on too strong. To be perfectly clear, I don't believe all starters will become the same if you use any reasonable level of care in handling them. That's all I was really trying to say. I wish it had not gone beyond that.

Craig
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Offline David Deas

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Re: do all sourdough starter cultures become the same?
« Reply #105 on: March 25, 2012, 09:07:13 PM »
You said I'm stuck on that. I'm simply asking where else it might come from?


Here is a good popular article I just found that explains what I believe can happen to a sourdough starter:

http://discovermagazine.com/2003/sep/featscienceof

....Since I apparently haven't done a very good job of being clear.  

In the end the author explains that the yeast don't change.  It's the bacteria that change.
« Last Edit: March 25, 2012, 09:10:59 PM by David Deas »

Offline TXCraig1

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Re: do all sourdough starter cultures become the same?
« Reply #106 on: March 25, 2012, 09:21:21 PM »
OK.
« Last Edit: March 25, 2012, 09:41:23 PM by TXCraig1 »
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Offline David Deas

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Re: do all sourdough starter cultures become the same?
« Reply #107 on: March 25, 2012, 10:30:14 PM »
David, I never meant this thing to turn into a fight. I apologize if I came on too strong. To be perfectly clear, I don't believe all starters will become the same if you use any reasonable level of care in handling them. That's all I was really trying to say. I wish it had not gone beyond that.

Craig

It's my fault.  I just reviewed the thread.  I did a poor job all around.  I wasn't clear.  I wasn't articulating.  My manners were bad.  Just looks like I was bouncing around too much.  Just an all around bad job.

Offline JimmyG

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Re: do all sourdough starter cultures become the same?
« Reply #108 on: March 25, 2012, 10:37:28 PM »
Chau,
Yeah... I am definitely down. I am pretty of curious how this is going to turn out given all the discussion. I am not sure how you want to standardize this experiment but I am game for it regardless. I am kind of hoping the room temp starter is different so I have a brand new starter to play with ;D. But I am not holding my breath either.

David Dees,
That is an interesting article. However, after reading through the article, my biggest question for the authors would be: if a culture can change over time, how long does it take before there is a shuffling of bacteria and under what conditions will that occur? As I eluded towards in previous posts, what is targeted under laboratory conditions will not always hold under everyday scenarios, something easily forgotten by both researchers and non-researchers a like. While I do think that the sourdough culture can change over time, I think the more important question is under what circumstances will this happen at? Hopefully, if there are enough individuals to join Chau's follow-along science experiment, this question can be determined by the Pizzamaking community.


Discovery consists of seeing what everybody has seen and thinking what nobody has thought.

Offline TXCraig1

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Re: do all sourdough starter cultures become the same?
« Reply #109 on: March 25, 2012, 10:51:24 PM »
It's my fault.  I just reviewed the thread.  I did a poor job all around.  I wasn't clear.  I wasn't articulating.  My manners were bad.  Just looks like I was bouncing around too much.  Just an all around bad job.

No hard feelings.  :)
Pizza is not bread.


Offline JimmyG

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Re: do all sourdough starter cultures become the same?
« Reply #110 on: March 25, 2012, 10:55:09 PM »
Additionally, I should add that this question regarding changes in flavor perception and sourdough starter maintenance over time has yet to be published in among the scientific literature. The result from such an investigation would not onlybe publishable but would also have applications  PM community, other bakers and the scientific community as well. It truly is an interesting question needing exploration.
Discovery consists of seeing what everybody has seen and thinking what nobody has thought.

Offline Grimaldi

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Re: do all sourdough starter cultures become the same?
« Reply #111 on: March 25, 2012, 10:57:01 PM »
I just wanted to tell you guys that you make me smile, getting into a semi heated discussion about sourdough! It's almost like we are talking about NDAA, Patriot Act, War and other pressing matters. Pizza grounds me - it is like an old architect friend of mine that is no longer with us used to tell me, "anyone can make things complicated, there is an art to keeping things simple." Simple is not easy.    
« Last Edit: March 25, 2012, 11:58:38 PM by Grimaldi »

Offline Jackie Tran

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Re: do all sourdough starter cultures become the same?
« Reply #112 on: March 25, 2012, 11:12:05 PM »
Jimmy I'm not sure if we can standardize this experiment or not and if the conclusions we draw at the end of it will even mean anything.  It would be great to see everyone get similar results, but somehow there will always be outliers, and how would that skew the conclusions we want to draw from this.  At this point, I'm not sure we have enough folks to even commit to doing this experiment for the results to be meaningful or not.  The purpose of this experiment would be simply to see if we can overtake a starter at room temps and 2) if take overs are possible, if they occur more readily at room temps versus a cold fermentation maintenance.  I have already determined that it isn't likely with cold fermentation.  However we can still use the CF sample as a control.

I would suggest using IDY, ADY, or CY as the yeast source because they are relatively flavorless.  If a new local yeast will overtake the starter, then it will be pretty evident as we are looking for a change in flavor of the starter.  As I said, if anyone is to do this experiment, you will have to commit to feeding the starter at least once a day if not twice.  You can't neglect a starter at room temps for 2-3 days, as it may create scenarios for take over and skew the results.

Of course you can use any existing sourdough starter if you want.  Just be sure it is something you are very familiar with the flavor so that if a take over occurs, you will be able to detect it the flavor change.

For myself this is the plan.   I have just started a CY starter, 10gm water + 10gm any flour (I'm using AP bleached) + a pinch of CY.  Whatever you decide to use, it should be active in less than 12 hours.  Once it becomes active, feed and maintain as any other starter at room temps of 75f.

Food source: will using bleached flour versus organic make a difference?  I use cheap AP bleached flour to feed my starters because it's cheap.  I am assuming bleached flours have less yeast in it.  Anyone know if this is true or not?

Feeding schedule:  I plan to feed my CY starter twice a day at 630 am and 630pm or there abouts.  I will be dumping the starter and retaining only 1gm of the active starter to be mixed with 8gm of water and 12 gm of flour.  This will give me approximately 8% starter seed in a ~68% hydration dough.  At 75f room temps this will take approximately 12 hours to become active.   This will ensure that if I miss feeding it by several hours, it should not overferment.  You can choose any type of feeding routine but it should be reasonable.  Yu can't really have a starter that becomes active in one hour and then not feed it for 24hours.  This type of scenario may drastically affect the health of the starter, I don't know.   What we are testing for here, is if a healthy starter that is maintained regularly can be overtaken by rogue yeast.

I will also be keeping a separate CY starter in the fridge that I will either feed weekly or not at all for the duration of the test.  I don't know, I haven't decided yet so you guys can tell me what you want to see.

Room temps:  everyone's room temp will differ slightly.  I'm using 75f b/c my kitchen typically averages 75.  If we can keep within 5f either way, I dont see that as having a significant impact on the results.

Length: 3-4 weeks or until the culture is overtaken if it happens sooner.  I think even 2 weeks is plenty of time for a takeover to occur if it is to occur.

results:  now suppose my starter develops acidic notes after 2 weeks.  Would this neccessarily mean that a new  strain of yeast has over taken it?  I'm not sure it would.  Could it be bacterial in nature?  Can bacterial cause sourdough type of flavors?  I'll leave this up to the the forum brainiacs to decide. 

So does that sound simple enough?  Can we get some folks to commit to this unscientific study.  Again the goal of this is to simply see if....

1) starters can be overtaken from local yeasts.  We will presume ths has happen if there is a drastic change in flavor of a raw starter.
2) if a starter take over is more likely at room temps versus cold temp maintenance.  

Thoughts and suggestions?  Do you guys consider this a fair, worthwhile, and meaningful experiment?  Any takers besides Marlon and myself?
« Last Edit: March 25, 2012, 11:25:12 PM by Jackie Tran »

Offline TXCraig1

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Re: do all sourdough starter cultures become the same?
« Reply #113 on: March 26, 2012, 12:10:39 AM »
Chau, I don't understand why you are are not starting with a sourdough culture? Isn't that what we are curious about here?

How about taking a sample of culture, dividing it in two and feeding the two as you have suggested but feed one straight flour and one flour that has been sterilized somehow? Vacuum packed and boiled maybe? Or perhaps the oven?
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parallei

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Re: do all sourdough starter cultures become the same?
« Reply #114 on: March 26, 2012, 12:21:35 AM »
Quote
Can bacterial cause sourdough type of flavors?

Yes.  I believe the lactic acid bacteria ARE what causes the "sourdough" flavor.

Acetobacter?  That would be a bacterium one that is not, I think, normally present.  Some might confuse a mild vinegar taste with a lactic fermentation.  Need O2 though.
« Last Edit: March 26, 2012, 12:32:27 AM by parallei »

cornicione54

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Re: do all sourdough starter cultures become the same?
« Reply #115 on: March 26, 2012, 12:38:38 AM »
Yes.  I believe the lactic acid bacteria ARE what causes the "sourdough" flavor.

Acetobacter?  That would be a bacterium one that is not, I think, normally present.  Some might confuse a mild vinegar taste with a lactic fermentation.  Need O2 though.

Heterofermentative lactobacilli may co-metabolise maltose with fructose which results in production of acetic acid. No oxygen required.
« Last Edit: March 26, 2012, 12:42:22 AM by cornicione54 »

Offline Jackie Tran

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Re: do all sourdough starter cultures become the same?
« Reply #116 on: March 26, 2012, 12:54:30 AM »
Chau, I don't understand why you are are not starting with a sourdough culture? Isn't that what we are curious about here?

How about taking a sample of culture, dividing it in two and feeding the two as you have suggested but feed one straight flour and one flour that has been sterilized somehow? Vacuum packed and boiled maybe? Or perhaps the oven?

Craig, I just thought a yeast culture that is relatively lacking in flavor would be easier to and definitively detect if and when the flavor profile changes, especially if I keep the feeding routine as I plan to.  I was also speaking to member Bakeshake and he related to me that he kept a CY starter at room temps that slowly changed flavors after several weeks.  Since he is repeating this test both at room and cold temps, I thought I would also do the test with CY.  

I know that a CY leaven or a commercial yeast leaven (poolish) isn't technically a starter, but do you think it would not be suitable for this test or somehow void the results.  I mean if a local yeast can overtake a SD starter, then it should also be able to overtake a CY or commercial yeast leaven as well right?  

Using a starter would be ideal, but it seems to leave too much room for interpretation if and when a new yeast has colonized, especially if the feeding schedule is not routine.  We are then dealing with under versus overfermentation, different levels of acidity, thus making the results potentially too unreliable and confusing.

I like your idea of cooking the flour to kill the yeast since yeast dies at 140f (thanks Google!).  Baking or boiling the flour should work and would be a good test to do.  I do like your idea for keeping 2 SD starters and feeding  with the sterilized vs unsterilized flour.  I'm not sure if this would create excess work and scare members from committing to keeping up with the experiment.

Chau
« Last Edit: March 26, 2012, 01:00:54 AM by Jackie Tran »

Offline Jackie Tran

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Re: do all sourdough starter cultures become the same?
« Reply #117 on: March 26, 2012, 01:12:22 AM »
Paul and Cornicione or anyone else.  Do you guys think the test would not be worth doing with a flavorless CY leaven?  As of now, my leaven isn't sterile and has bacteria in it but yet I don't taste any acids or sourness even when it is fully active.  I only smell and taste a slight fruitiness that is common to my particular CY.  If any new flavors develop, I am confident I will be able to clearly and without question discern it.  

My only concern then is that some new strain(s) of bacteria will be introduced into the leaven creating acidic or sour notes that would lead me to believe I have a new yeast colonizing in my leaven when there is not.  Surely, this false or misguided conclusion would definitively void the test, would it not?

Since there is no doubt bacteria already existing in my CY leaven, is it possible that there is a symbiotic relationship there much like what occurs in a natural SD starter?  Can whatever bacteria currently cohabitating in my CY leaven prevent other new bacteria from moving in?

TIA,
Chau

Offline TXCraig1

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Re: do all sourdough starter cultures become the same?
« Reply #118 on: March 26, 2012, 01:13:13 AM »
Iím thinking that using bakerís yeast is not in the spirit of the original question as that species of yeast is not found in sourdough cultures.  It is my memory from reading things on Google, that it is almost never found in healthy sourdough cultures, even in trace amounts. I donít think it can take the low pH. If that is the case, it would seem to be a certainty that the wild yeast/bacteria in the flour would be able to take over. However the results would not necessarily be relevant to the original question which pertains to sourdough cultures Ė not bakerís yeast cultures.

Remember, you have to kill the bacteria in the flour too which probably means heating to 250F t be sure ruling out boiling (Google).

CL
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Offline TXCraig1

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Re: do all sourdough starter cultures become the same?
« Reply #119 on: March 26, 2012, 01:21:08 AM »
With the aggressive discarding and feeding schedule you proposed, will you not keep the pH artificially low? If a low pH is a component of a healthy culture, and I believe it is, perhaps you give an artificial advantage to organisms that can't survive in a low pH environment - opening a door that would otherwise be closed?

Why not feed on a schedule typical of what one might ordinarily find? Once every two or three days or so, discarding and feeding 50%. Whatever Ed Wood reccomends is probably a good choice.
Pizza is not bread.