do all sourdough starter cultures become the same?

[Jackie Tran]

I'm about to try to revive my now throughly mistreated culture samples and see how they compare to the happy, fed ones sleeping in the fridge once activated.

So Craig, it's been sitting out at room temps for a week or so now without any feedings right?

[TXCraig1]

Yes, coming up on two weeks at 75F without feeding.

[JimmyG]

So I started my follow along experiment this morning. Below I am providing some detail of how I am proceeding:

   For this follow along, I left four samples out on the counter, two were left open in a closed Tupperware container–with a wet sponge in the bottom for humidity. The other two samples were left in their own closed containers on the counter. One test sample in each group– the open and closed groups–contained my SD culture and the other sample contained only flour and water. Flour (KAAP) and water was mixed in a 1:1 ratio to each other and provided the base for all samples. If it is possible for a take over to take place, I hypothesis that closed container group should taste different and the open containers should taste similar to each other. All samples will be feed every once every 48h for 10 days.

[Jackie Tran]

Your experiment sounds interesting Jimmy.  Can you clarify your hypothesis?  Are you hypothesizing that the 2 samples of the closed container group should taste different from eachother or that the closed container group as a whole should taste different from the open container group?  Can you take me through your thought process on your hypothesis?

For example.  Do you think that a take over is possible with the only flour + water sample of the open container group, and if so, where would the invading yeast come from?  The neighbor SD starter, flour, or airborne? 

Also at what point in the fermentation process will you be doing the final taste testing for the verdict?  At the end of the test and prior to taste testing, I imagine you will have to feed all 4 samples more frequently than every 48 hours to get them to peak activity prior to tasting.  I imagine you would want to do multiple taste tests of the starters at different stages as well as each starter matures and becomes more acidic.

[JimmyG]

These are great questions Chau. To clarify, my four hypothesis are:
1.) If airborne migration is the primary mode of invasion, I would hypothesis that the open container groups (samples 1 & 2) should become very similar to each other in a closed environment at the end of the experiment.
2.) If the cultures are able to migrate (airborne) the flour and water samples (samples 2 & 4) should taste dissimilar at the end of the study, as both groups have been exposed to different environments.
3.) If yeast and bacteria already present in the flour are the primary vehicle for invasion and the origin of all SD starters, I would speculate that the flour and water samples (samples 2 &4) should be dissimilar to the SD samples (samples 1 & 3).
4.) Also, if SD starters are hardy enough to withstand invasion by outside flora, I would hypothesis that the flavor of both SDs (samples 1 & 3) will not change throughout the experiment.  

Hopefully this should cover many of the questions we have asked throughout this thread.
I should add that I will be feeding the flour and water sample in its own closed container (sample 4) first to minimize any airborne transmission from the other samples. The other samples will be feed in corresponding descending order.

Here is a diagram of the design for further clarity.

                                        SD Starter          Flour + H20      
Open containers in a              Sample 1           Sample 2
closed environment

Closed containers in a            Sample 3           Sample 4
open environment

Yeah I will probably taste in between feedings but I will rely on the final tasting to draw my conclusions.
Regarding final tasting, I think what I will do is feed on the 10th day (in the morning after coffee) and taste the raw starters 8-12h later that night. This should give ample to time for the cultures to mature at room temp. I may at that point make up four AP doughs to see if there are any noticeable flavor or other physical (eg color, oven spring etc) differences between the crusts after baking too.

I am also considering starving the entire group for 10 days after the final feeding to see if anything happens but we shall see.

Addendum: I should also add the only way I can validate any of these hypotheses is to assume that I will find differences in flavor in at least one of the samples. If all of the samples taste the same in the end or are completely different from each other, I am stuck back at square one and am not able to draw any conclusions. Here is hoping there is a detectable difference.

[JimmyG]

This morning I feed all samples with a 1:1 mixture of H20 and KAAP and made a preliminary tasting of the starters. Samples 2 & 4 (flour + water group) were beginning to show some activity but still tasted pretty doughy. The SD samples had retained their activity and still tasted remarkably similar. The only noticeable difference was that sample 1 overflowed out of its container while sample 3 never reached the top of the lid. Ill report back in a few days with any progress being made.

[Jackie Tran]

Just wanted to give an update on my experiment.  It has been about 2 weeks now of feeding 2 starters (ischia & patsy's) and a CY leaven/culture at room temps once a day.  The hydration for all 3 was approximately 70% by feel/eye and they were typically fed around 9-10pm daily.   I would smell them first, then taste them usually before feeding and occassionally in the morning or midday.   Prior to feeding most days, all 3 were usually liquid and bubbly and rather acidic.  At first the CY culture really had no acidity but after 3-4 days I started noticing some acidity, while the other 2 were always acidic by feeding time.   At the end of 2 weeks, the acidity of the CY leaven is still present but less than the other 2.

Last night, I forgot to feed at 10p, but rather did the feeding this morning at 6am.  I decided today was test day, so at 6am this morning I discarded the majority of each and fed all 3 with 50/50 flour & water.  I wanted to bring them all to the same point that I would normally use them at 100% hydration.  I also pulled the 2 corresponding starters and CY leaven from the fridge and also discarded & fed them.  I spent most of the day discarding and refeeding all 6 samples so that they would all be active and in a similar youthful state at time of testing.  I didn't want any residual acids in any of the samples to interfere with their tasting or aroma at test time.   Testing was done tonight at around 8pm.  All starters are considered fairly young and all are similarly active.  

I first tested each room temp sample that had been split from their original counterpart (fridge maintained) and was pleased that all 3 tasted very similar to their counter parts, with the exception of the room temp Patsy's and Ischia starters having a little bit of an off odor (bit stinky) compare to the fridge samples.  I did multiple taste test, and was happy to conclude that though the aromas differ slightly for the patsy starter, the taste was very similar.  

I also noticed this about the CY leaven.  The fridge sample smelled slightly sweet as it always does while the room temp one smelled just slightly acidic, but not to the same degree as the other 2.  Both tasted very similarly to one another with a slight sweetness with very little acidity to them.  

After multiple taste testing between all 6 samples, I started noticing that the flavors were ALL very very similar.  Upon noticing this, I cross taste tested all of them against one another (ex. Patsy vs Ischia (RT and fridge), Ischia vs CY (RT and fridge) so on and so forth).  The only slight difference between all the samples is both CY leavens (Room temp & fridge) had a slightly milder flavor, but I would say that it is the same flavor as the others.  Both the room temp Patsy and Ischia have a slightly stinkier aroma compare to their fridge counterparts, but all flavors are very similar.  I would say the room temp Patsy's and Ischia smell and taste identical.  Where I once was confidant that I could distinguish starter from starter blind folded, I am no longer sure about that.

Where I once was so sure about the uniqueness of my starters, I am no longer sure about that either.   At this point, I plan to put them all in the fridge and I'll continue doing taste testing in the future, but as it stands these are my results and I am convinced that they are all the same or very similar now.   Perhaps I have been wrong about all of this.

Chau

[David Deas]

It will be interesting to see if you can restore them. 

Reviving starters, I have done often enough.  Whether or not a starter can be *restored* to its original state after a substantial period of neglect, I have no idea.  I've never paid that close attention.  I'm usually just preoccupied with making sure the revived starter is not too sour for use.  And then I'm good to go.

In theory your starters should restore.  But then again, I probably only know half the theory.

[Jackie Tran]

One thing I failed to emphasize in my post is that the starters smell differently at their peak.  The fridge CY and Patsy smelled slightly sweet when brought to room temps and active.   The 2 week room temp Patsy's and Ischia we're a bit stinky...bacterial odor, not heavy but noticeable.  At first I thought it was because I had too much residual starter to start with, but even after discarding 90% plus and reseeding, which I thought would make that odor go away, it was still there even after several feedings.   But the taste between all of them were very similar.  I was also tasting 1/4 -1/2 tsp at a time to try get a really good taste.

[JimmyG]

One thing I failed to emphasize in my post is that the starters smell differently at their peak.  The fridge CY and Patsy smelled slightly sweet when brought to room temps and active.

That is pretty interesting that you are finding differences in the smell but not flavor. Do you think the acids being produced in your RT samples are masking other odors?

[David Deas]

Great thread.

I actually have three totally dormant starters that have all been at room temperature for months without food.  I can revive them at any time.  However, I cannot really get involved here with them unfortunately because I have no way of objectively determining what they were originally like.  I have some idea about it, but no truly objective measure one way or the next.

Darn.

[Jackie Tran]

That is pretty interesting that you are finding differences in the smell but not flavor. Do you think the acids being produced in your RT samples are masking other odors?

Jimmy, all samples had very little acid in them.  I would use around a 10-20% young seed, feed, and it would be ready in 4-5 hours.  I then discarded again and refeed, so there was very little residual acids in the seed.  Any acids produced during the 4-5 hours was a very small amount.  I'm not sure how much they are really masking odors or flavors.  I think what I am mostly tasting is the break down of the flour, some bacterial and yeast fermentation, and a very small amount of acid, which might partially explain why they all tasted so similar.  The similarity in flavor could be attributed to the way I fed them at room temps throughout the day, but I don't know enough to say.  Just reporting what I found...

Looking forward to your results.

Chau

[Jackie Tran]

Great thread.

I actually have three totally dormant starters that have all been at room temperature for months without food.  I can revive them at any time.  However, I cannot really get involved here with them unfortunately because I have no way of objectively determining what they were originally like.  I have some idea about it, but no truly objective measure one way or the next.

Darn.

It would still be interesting to see if they all taste similar or different once revived.  That would still be important to know.  Will you consider reviving them and posting your findings David?

[David Deas]

Sure. 

Choice of flour?  Any in particular?

[Jackie Tran]

Whatever you have on hand. Thanks!

Chau

[TXCraig1]

I do have an Ischia and a Camaldoli starter that I'm going to leave on the counter for two or three weeks (a little less than a week so far) and then revive and see if there are any differences compared to each other and the controls in the fridge. There is no doubt that they were very different before the start in both flavor and behavior.

After 2.5 weeks on the counter at 75F without feeding, last night, I took 1Tbs of each and 1Tbs of each of the mother cultures from the fridge and mixed each with 1/3c flour (KABF) and 1/3c water. So, there are a total of 4 samples growing, 2 Ischia and 2 Camaldoli. All showed some signs of activity this morning. Those from the mother culture showed the most activity. I'll feed each another 1/3c flour this evening.

CL

[Jackie Tran]

Looking forward to your results.  At this point, do the previously neglected samples smell any different at all?  When refeedIng, how much of seed are you using?

[TXCraig1]

The two cultures from the counter both stunk. The Ischia had become so acidic, the lid was rusting and some condensed humidity dripped some rust down into the culture.

I planned to feed exactly how I would in an ordinary scenairo. This means I'll just add more at the next feeding. On subesquent feedings, I'll discard about 1/2 and replace with a like amount.

CL

[JimmyG]

I have some news and interesting preliminary findings today. First bit of news is that Sat. morning I had to restart my experiment. Friday night I had some friends over and someone got into my containers (I am guessing they were looking for food and thought it may have been dip or something). Not wanting to risk that my samples were contaminated I started over from scratch with fresh containers and vessels. The only modification I made was to closed environment group. To ensure a tighter seal, I overlaid the container with saran wrap, secured by a rubber band before applying the lid.
   What is surprising this time is that the closed environment flour + water mixture (FW) rapidly developed over the past 48h as shown below. In all photos, the sample on the left is from my original SD culture and the sample on the right (with the piece of white paper under it) is the flour and water mixture. The SD starter had exhausted it’s food supply over the two days. The flavor of SD starter had not noticeably changed from the original seed culture and was sharp, with slight acidic notes. The FW mixture was showing activity and bubbling–whereas there was no activity yesterday. While it is a little early to identify whether or not this was due to the neighboring SD starter, the flavor of the FW was different from the SD. The FW tasted mildly sweet and pleasant.
   Within the open environment/closed container samples (not shown), the SD starter had also used up it food supply and tasted the same as the closed environment SD starter. The FW mixture had no pronounced activity occurring yet and tasted rather bland.  Against protocol, I fed this group first this morning and did not recognize anything out of the ordinary until I viewed the closed environment group, which is why I did not snap any photos. I will try to get some photos of this group in two day when I refeed again.
   I am kind of curious about what I going on in the closed environment group. I am sure that I did not cross contaminate the FW mixture in the closed environment as the glass vessel was sterilized before the FW mixture was added and the FW mixture was mixed in one batch and divided between open and closed environment groups.
   If any members have time, could someone try to recreate this closed environment group, even if it is for only two or three days. My reason for asking is to validate whether or not I contaminated my FW sample along the way or if this is an actual occurrence, possibly being facilitated by the humidity in the container.  
   The container is a standard Tupperware container to which two sponge strips had been added. The sponges were saturated with water and placed at the bottom of the Tupperware.The container was tightly secured with saran wrap, a rubber band and the original container lid. The FW mixture was mixed at a 1:1 ratio with nothing else added to it. The SD mixture was 10% seed culture and 90% flour and water in equal proportions.

[JimmyG]

More pictures: