do all sourdough starter cultures become the same?

[JimmyG]

You bet. 

[JimmyG]

Yesterday I feed all the starters and this morning I again tasted all four starters in between feedings. The results have not changed since I lasted posted. Three of the starters, the two SD and the FW mixture in closed environment/open container sample, all tasted uncannily similar. The fourth sample, the FW mixture in the closed container/open environment group, is distinct from the other three starters. This starter has a citrus-sweet flavor, whereas the other three starters have the same astringent sour flavors. Tomorrow, I will be conducting a final feeding unless others have a reason to keep this going. I plan on feeding in the morning, 8h later, tasting and a final tasting the next morning.

[Jackie Tran]

Sorry if I didn't make my request clear Jim.  Can you keep the 2 different FW starters in a closed environment next to eachother with open tops/containers for a couple of days?  So that is with their lids off, but in a closed environment to ecourage take over.  I was curious  to know if the older starter and presumably stronger one would easily take over the new and presumably weaker FW starter. 

Or another idea, take a small sample of any of the other 3 starters and introduce it directly into the new FW starter (the sweet one) and see if it will and how it will change over the next 2 days.  I think I like this idea better.  Im curious to know if you will think if the older more established starter will completely take over or it will coexist with the new starter and display characteristic tastes and aroma of both parent starters? 

thanks,
Chau

[JimmyG]

Chau,
I am liking both of your ideas. After I finish with this last round of feedings and tasting, I will divide the new FW starter into two separate experiments like you outlined.
Just to make sure I am on the same page, below is the tentative plan as I understand it.
In two closed containers, I will separately maintain the new FW sample for comparison and in another container, I will equally mix, by weight, the new FW starter with the original SD to see if one dominates the other. In a closed environment, I will add in two new open vessels, one containing the new FW starter and the other containing the original SD, to see if one can take over the other with time.

Chau, do you think should I be mixing the two starters together before they are refed, when they are both in a starved state, or should I mix them together after they both had been refreshed and both starters are strong and healthy? Or does it even makes a difference?


 

[Jackie Tran]

Jim, it sounds like we are on the same page. 

As far as how much of each to mix in and when, that's up to you.  I was thinking like 75/25 new starter vs established starter.  The reason being is that if a take over is to happen, then it won't matter if we give the advantage to the new starter since it may not theoretically be established or strong yet.  And if you can still get a takeover to occur despite the disadvantage, then that would show the takeovers can occur readily, without much difficulty.

I would mix the starters when they are active and doming, then refeed.  Be sure to feed with a similar amount and taste it at the same point of activity with each successive feeding to see if you can detect if and when the change occurs.  Then when you are satisfied with your results, you can taste test them against your originals to confirm your results.

Thanks,
Chau

[DNA Dan]

Another thought is start off with say a very small innoculation. 1/8th tsp. or less. If you were to contaminate your starter, chances are it would be from just a few colonies and not some huge 25% or more amount by mass. If the starter doesn't change over a few days, try it again with a larger innoculation. Just a thought. This is a very interesting experiment.

The three that are similar in smell/taste ( even if the strains are different), all produce a lot of the same compounds. Most people cannot discern differences in minor percentage ratios of the same compounds. They may be 90% or more producing the same compounds, just in different ratios. What may be a larger influence on the ratio is how the starter is maintained. If you took one of the three and say kept it in the refridgerator and changed the yeast/lactobacillus ratio, it would have a much greater influence on the overall characteristics of the culture. Great work, I'm loving it!

[johnnydoubleu]

I wonder how long it would take to wash away contamination or if it would even be possible.

Guys, in consideration of your recent experimenting, what have been your major takeaways? Anything surprise you?

[JimmyG]

I have not updated in a few days due to being buried with student term papers, complaints, and life in general.  I am going to conclude my findings from the first experiment and give a heads-up on where I am at with the second experiment.

In the first experiment I created a 2x2 experimental design. The design was outlined here:  http://www.pizzamaking.com/forum/index.php/topic,18283.msg180418.html#msg180418 and here http://www.pizzamaking.com/forum/index.php/topic,18283.msg180435.html#msg180435
and is diagrammed as:
                                        SD Starter          Flour + H20      
Open containers in a              Sample 1           Sample 2
closed environment

Closed containers in a            Sample 3           Sample 4
open environment


All samples were maintained for 10 days, and fed in 2 day intervals, to evaluate whether SD starters would change over time or if SD starters could takeover another starter.

In short, the results of the experiment found that Samples 1, 2, and 3 tasted identical after the 10 day period. Sample 4, however, developed in to a distinct starter with flavor characteristics not found in the other three starters.  These results would suggest (1) that when properly maintained, mature starters are able to retain their original characteristics–over time–if they are fed on a frequent basis, (2) in a closed, and well humidified environment, SD starters are able to take over new starters which have not yet been established, (3) that new starters can be established in the presence of other active starters without worrying about a takeover, if the new starter is regularly fed and is isolated in its own container.

As recommended by Chau, I have started another experiment. For this experiment, I am retaining same 2x2 design. I have kept samples 1, 3 and 4 the same as above. Sample 2 was replaced with a sterilized vessel to which 50% of sample 4 was added during feeding and the other 50% was the same flour and water fed to the other three samples.  I am going to keep the same 2 day feeding regiment over the next 6 days. I am currently at day 2, so there will be 8 days total. As of this morning, I have yet to find any notable changes in any of the starters.

[JimmyG]

I wonder how long it would take to wash away contamination or if it would even be possible.

I would doubt it would be possible unless you killed the starter off and inoculated the contaminated starter with a the original starter which would be redundant.

[johnnydoubleu]

Jim, thanks so much for your efforts. Very interesting...

[JimmyG]

Just an update. I tasted both starters this morning, they both taste distinct but not as much as when I first started this second experiment. My old SD starter is beinging to take on some sweeter, and less sour notes that were not present before. I will note that the closed environment smelled like an all-night frat party took had taken place, so I am not sure if these flavor were due to aerosolized volatile alcoholic compounds or if something else is taking place. I will report back in a few days if things change.

[cornicione54]

@JimmyG
Thanks for your detailed account of your experiment(s). A quick question re: the FW sample that lived in a closed container in an open environment (sample 4?) - Discounting any dramatic rise from leuconostoc/enterobacter in the first 4 days or so, does it show a consistent leavening ability?
 
I ask because I've been experimenting with various (roller-milled) white flours over the last year to see if white flour + water alone can be reliably employed to yield a useable starter culture.
So far I have consistently achieved "sourdough flavours" (covering the gamut of aromas/flavours you describe in your previous posts) but none of the cultures showed strong leavening capability. I concluded that it was relatively easy to establish a LAB population which will create a small amount of CO2 under the right conditions (heterofermentative pathway). However establishing a significant wild yeast population in starter cultures without the use of whole grain flours (as I have done with consistent success in the past) has proven elusive.

So I'm curious to hear how your FW culture has fared in that regard?

[JimmyG]

...the FW sample that lived in a closed container in an open environment (sample 4?) - does it show a consistent leavening ability? (discounting any dramatic rise from leuconostoc/enterobacter in the first 4 days or so).

   I saw activity by the fourth day in this sample, but it wasn't until 8-10 days when I noticed a consistent pattern to the leavening in that starter. I will tell you too that this new culture has a fast doubling time but does not have a very pronounced sour flavor. The flavor of this new starter is sweet and it puts off a ton of alcohol. I have no idea why this one is so fast or how to cultivate this type of yeast strain. Just the luck of the draw I guess.
    My old SD starter by comparison, is very, very sour (almost overwhelming at times, if not beaten back with a healthy dose of salt), but is sluggish in the doubling department.  I have noticed that yeast activity improves with a little more salt (2.35%), if I ferment it between 60-65F, and when my final dough has increased it size by only 1.5x. If I bring it to a full double using starter, it will have significantly weaken the gluten and acidified the
dough.
As a side note: the photos of the drunken pies I made this weekend, found here: http://www.pizzamaking.com/forum/index.php/topic,18932.msg184826.html#msg184826 were made with the new starter.  

[cornicione54]

Ah thanks for the info Jim. Sounds like your new starter is a winner.
 
Loving those "drunken" pies btw

[JimmyG]

Ah thanks for the info Jim. Sounds like your new starter is a winner.
 
Loving those "drunken" pies btw Smiley

Thanks. I am pretty happy with this new starter so far. Made a great bread out of last night.

[JimmyG]

Update: So there have been two feedings since I last posted and I am not sure whether or not I should be continuing with this experiment or not. The boozy aromas coming from the new starter are permeating everything, making it hard to distinguish between the starters once they have doubled.

The two starters in the closed environment have became similar and I am not entirely sure it is due a take over.  My new starter is very boozy and is releasing enough volatiles throughout the container that it is permeating everything. About 8h after feeding, I can taste still taste that the starters are distinct but after that, the booze flavors take over making it difficult to distinguish between starters.

I can keep going if you folks would like, but I am not sure if I am going to be able to draw any good conclusion from this experiment.

I can start up the inoculation experiment Chau recommended a while back if anyone would like, however I am a little worried that the same issue may arise in this experiment as well.

I should note that the two starters left in their own separately enclosed containers have not changed.

[DNA Dan]

Boozy? What is this new starter you are using?

I don't know if the innoculation experiment is worth the time. I mean the competition for dominance in the culture is going to depend on the health of each starter and how much innoculum you use. This will vary by starter since some are "weak slow growing" and some are "Crazy fast growing".

I don't know you'll really gain anything from that.

[JimmyG]

Boozy? What is this new starter you are using?

It is hard to describe the smell, but it kind of smells like the original Falstaff beer mixed with lemon pledge and honey. I know that sounds strange but that is what is coming out of the starter.  

In any case, I am going to consider this last experiment as a fail for the time being, and terminate it.

[Jackie Tran]

Boozy? What is this new starter you are using?

I don't know if the innoculation experiment is worth the time. I mean the competition for dominance in the culture is going to depend on the health of each starter and how much innoculum you use. This will vary by starter since some are "weak slow growing" and some are "Crazy fast growing".

I don't know you'll really gain anything from that.

I dunno, I disagree.  Is any experiment worth anyone's time? Of course there are always going to be unknown and uncontrollable variables, variations in starter strenth and health, etc.   Anyone can sit and theorize whether take over is likely or possible.  You won't know for yourself if it is possible until you do the experiment.  It's okay that we even get different results, but I truely believe there is always something to be learned in doing any experiment no matter how wacky it sounds. 

I have my own opinions on the experiment in question and would like to know Jim's thoughts on it.  Jim, I'm sure you are tired of caring for these starters for awhile now.  I don't think it will take but 2 days to tell if anything will happen with them.  Who knows, maybe you will be suprised. 

I know I was when I did my experiments earlier in this thread.  I don't believe at that time anyone could convince me that take overs were possible.  I did the experiment and changed my opinion.  Yes it was worth doing.   

Chau

[JimmyG]

Chau,
I do think your right, you never know what the results might be unless you try. I can mix three separate batches this weekend containing varying proportions of the two starters to see what happens. My only real concern at this point is that the residual SD flavors from first inoculation may bias any findings and may not be entirely reflective of a true take over. That said, I can certainly give it one last go.