Thing One and Thing Two
“The sun did not shine,
It was too wet to play…” From “The Cat in the Hat” Dr Seuss
Yes, a day of rain and record cold in the Mile High City and we all go nuts. We aren’t accustomed to anything but sunshine.
So I decided to finally write up my two levain experiment.
The question that was innocently asked: Why does my levain, with my less than precise maintenance routine still live, thrive, and reliably raise bread? In theory, it should be dead. But it is not.
BWraith had put forth the theory (and I tended to think it reasonable) that I might be raising a bunch of l. pontis which is typically found in culture with a low feeding ratio. We also theorized that if I changed the feeding ratio, the levain would struggle a bit, but a transition to a different lactobacillus would occur.
So for the past few months I have been maintaining two levains. One, my beloved Thing One, fed as usual. Once a day – Thursday through Sunday, “some” of it is removed and it is fed with 4 ounces each of all purpose flour and water. No exact feed ratio – just me eyeballing “some” based on- well, whatever it is I base this on. Sunday afternoon to Thursday evening it is kept in a special refrigerator at 50F. Thursday through Sunday it lives either on the counter in my kitchen, or during particularly hot days in my cool basement. (Yes, I know, once a day isn’t enough. And yet, it is…)
Thing Two – created from Thing One – was fed at a 1:5:5 ratio over that period of months. It never left Thing One’s side – so it lived under the same conditions and schedules. I was as careful as I could be about cross contamination.
Would they be different in any way?
During the summer I still baked something each week (You gotta eat…). I alternated between Thing One and Thing Two. To be honest, I was unable to tell the difference in any of my baking. Thing Two did not struggle or fail to double at any time.
But if I did any analysis, would they be different?
.2 oz of a ripe sample of each in a container showed me (if it is not clear in the picture) that they were practically identical. Thing Two was, however a bit stiffer, probably reflecting the fact that the gluten had not degraded as much as that for Thing One – which seems reasonable.
Mixed with .4 oz of distilled water (so that a pH strip could be used) they each showed a pH of 3.5. It had been theorized that the pH of Thing One should be lower – but no – they were identical.
Each sample was mixed with .4 oz of all purpose flour and allowed to ripen for four hours. Both rose nicely and well, I’ll be horn swoggled if I can tell the difference. If I hadn’t labeled them, I wouldn’t be able to tell.
So what have I learned? Uh, nothing? That the inner life of levain is a deep mystery? Just how determined those guys are to live? That I need to get out more?
I have been unable to find anyone willing to determine just which variety of lactobacillus is living in my levain tubs, but would welcome input from anyone who could help. Or any insight (Bill…) at all.
I really don’t know. I do know that a practiced hand and eye counts for something in this bread making business and I’ve been tending Thing One for years. It could be that we just “get” each other.
Happy Baking!
Comments
Hi, Pat.
Your irregular, slapdash feeding of Thing One is so much more regular than the way I feed my starter!
I don't really have a regular schedule. I keep my starter pretty firm, at least when it's first fed. I feed it with a 1:3:4 ratio of starter:water:flour. The thing is, I actually feed the refrigerated starter less than once a week. Most often, when I'm going to bake, I take some starter from the refrigerator, activate it by mixing the above ratio and leaving it on the counter overnight. I then either use it to make dough or refrigerate it until the evening.
I don't know how fast it doubles, but it has doubled and, sometimes, partly collapsed by morning. It raises dough just fine. It smells wonderful. The bread tastes wonderful.
Now, if I happen to be making a bread with an "intermediate stater," i.e., an activating feeding, then another feeding 8-12 hours later, the second levain doubles in 4 hours at 72-75F, so I know it gets ... well ... activated by more frequent feeding, even just 2 feedings.
I replace the refrigeated starter with newly activated starter whenever my stock starts to get less viscous. This may be every 3-4 weeks.
Now, I know I am committing sourdough sacralige. The thing is, it works for me. It's been ages since I've seen any hooch, even when the refrigerated starter is like thin soup.
I am of the opinion that, if you have a fundamentally healthy starter, it can adapt to your feeding schedule. It may be that the balance of organisms is different with my brand of "neglect." Whatever. The starter makes good bread.
So, if I understand your experimental conditions, I think the difference between what you did with Thing one and Thing two may not be sufficiant to make a difference. If I took some of my starter and fed it daily and compared that to my present starter fed as above, THAT would be a difference.
Building a healthy starter from scratch probably requires more diligence, but my starter seems to keep going in spite of my neglecting it.
David
I would feed my starter once a day - but it is not a perfect world...
One would think that such an extreme difference in feeding (replenishing 4oz or so of starter with 4 oz of flour/water versus 1 oz of starter with the same amount of flour/water - that's a big difference - Imagine feeding your Great Dane the amount of food you fed your Cocker Spaniel...)would have made some impact.
I keep going back to the thought that sourdough was the only method of raising bread for more centuries than commercial yeast. Now, I don't claim that medieval bread represented the ultimate in refined baking, but I also think that these little guys had lives at least as tough as the bakers who tended them.
During this time I also decided to nurture a starter from scratch just to see if I could. Perhaps my house is permeated with micro flora - but it started easily and got to an acceptable strength with the same feeding method I used for Thing One. I got tired of feeding three starters, dried some of it for posterity and disposed of it sometime in July. But it was a good little starter.
My hands, my dough, my levain. That's what makes us artisans.
Pat,
Very interesting experiment and thanks for sharing.
For a long time I only fed once a day as well and not enough flour. It still made great bread. Mike told me to feed more, more often. I did that and my starter went wild. But I can't keep it on the counter because it doubles each time and hate throwing out. So, now I have absolutely NO schedule, put it in the fridge, take a couple Tbsp to build a starter for bread, sometimes use the new one that also doubles to make another bread, sometimes chuck it and take the one in the fridge to make new, sometimes chuck the fridge one. Sometimes the one on the counter gets left for over a day, but once given a good feeding, it comes back to life immediately. I don't ever weigh the flour I use to feed. Basically I look at how much starter I have, then probably triple it in flour, add a little water, stir, check the consistency. Sometimes I leave it pretty thick, sometimes a little thinner, sometimes make a firm. It depends on how fast I want it to mature and what I'm making.
So, what's the conclusion? I'd say that what David and yourself concluded is valid. The culture is so strong and adapted to it's environment that it just goes with the flow !
Jane
So glad that you found it interesting. I always think that these little experiments are dry - useful, but dry.
I can actually hear the voice of a teacher saying "Would you put your grandmother in the refrigerator for a week?" and I always feel guilty when I shut the door on my levain. But as I said, it is not a perfect world...
The only thing that worries me a bit is something I read, in one of the many books, about the "possibility" of certain bacteria (or yeasts?) dying at under 8°C. But then, I haven't ever seen a difference and though I am strying for "perfection" I'm admit to never taking dough temperature or worrying about so extremely subtle difference in flavour due to some strand of bacteria dying in the fridge. It all seems to work just fine... but what if?
Jane
It's a pretty common practice to refrigerate a starter. I think the possibility for problems is pretty remote.
Of course, I bought a tiny 'fridge and keep it at warmer than normal temperatures to store my levain, so who am I to talk?
Pat
I always put them in the bottom part of the fridge because it's supposed to be the warmest (or less cool). Regardless, it can't do too much damage since I have been known to feed a starter and put it in the fridge without it even having a chance to develop and the next morning, it is in full action. I can just take it out, let it warm up a bit and it is ready to go.
Jane
for a week or longer if she was properly dressed and preferred cool weather. Naturally the fridge would have to be big enough to accommodate all her friends.
The comparison is really absurd.
No one keeps a starter as big as their grandmother (quiet Mark) or maintains a warm blooded starter.
Mini O
My response was that I would certainly put my mother in the refrigerator for a week, but probably not my grandmother.
I believe what the individual was trying to communicate to me is that the better care you give your levain, the better it will perform. Although refrigeration is common and often required for practical reasons, it is certainly not ideal. During an unusual month where I did have the opportunity to feed my levain every day and skip the refrigeration, I saw a dramatic improvement in how it acted. This is not to say it doesn't work for me now that it has to live for a few days in the refrigerator - but tended and fed every day, it was extraordinary.
I provide the quote (which is a real quote - from a real person other than me) for some humor.
I am sorry it offended you.
At the temperatures we've been having lately, I'd put myself in the refrigerator! :)
I've done both the refrigerated starter protocol (with feeding at room temperature for 3 cycles before baking) and the twice daily, "continuously at room temperature" protocol and have found that I get better results with the latter. Your results might vary. Some people might say that a continual twice feeding regimen uses too much flour, but I keep only about 100 g of starter at a time. And besides, if people can feed their cats and dogs continuously, I can do the same for my starter! :)
SteveB
www.breadcetera.com
Of course, the Mile High city is a refrigerator right now.
I don't think I would refrigerate my starter at all if I didn't need to. But the question that baffles me is after years of once a day feeding, my starter does not seem to be suffering. It should be, but it is not. Great smell - dough doubles in one to two hours - nice taste. I have nothing to complain about.
Unlike keeping it out of the refrigerator, feeding it twice a day didn't do much for it. Frankly my situation keeps me pretty busy - sometimes I only get to eat once a day.
Do you have any insight on why this routine works? Could it be the periodic refrigeration? Or why when I drastically changed the feeding routine (and I have done this for months) that I would experience no change? I've done a pretty good literature search, but a different viewpoint is always helpful.
I'd be happy to hear it because it kinda baffles me...
Thanks for any insight!
Pat
I'm not sure I have any great insight to give, but I think of things in the following way: When a culture is first fed, the yeast sequentially undergo a number of stages, two of which are the aerobic reproductive phase and the anaerobic fermentation phase. Both phases require food but only the first requires oxygen. The oxygen is used up rather quickly so reproduction has a relatively short time to occur.
Just speaking about room temperature feedings now, as the time between feedings increases, either the added flour (food) needs to increase or the amount of innoculant needs to decrease so the culture doesn't run out of food before the next feeding. However if the ratio of food to innoculant becomes too high (perhaps this is the case with once a day or fewer feedings?), at the end of the short-lived reproductive phase, there is a relatively dilute concentration of organisms which becomes more and more dilute with each feeding cycle. This would ultimately lead to a very weak culture that could not sustain itself. So, the time between feedings, the amount of oxygen incorporated and the amount of innoculation appear to me to be key.
I'm the first to admit that the above description is only how I think about it; it seems to explain what I've seen empirically but I have no real data to suggest that this is what is actually happening. Let the reader beware! :)
SteveB
http://www.breadcetera.com
What you described was the theory that I was trying to test. So by feeding Thing Two at a way higher ratio than ThingOne, I expected to see a difference.
But I didn't.
So after years of feeding at a low ratio (and once a day) - I still have a healthy levain that can obviously sustain itself.
The theory was put forth that I had a different dominant strain of lactobaccillus (l/ pontis) and that the change it feeding might shift it and that a leading indicator would be pH.
Again, after quite a few months, I saw no change.
I'm all for making an effort to take excellent care of the levain. If I had any problems with it (and I don't) I'd jump on the twice a day feeding bandwagon. But short of getting an analysis to determine the dominant strain of lactobaccillus (and from what I read, these bad boys can change and evolve to create new sub-groups [sorry - engineer - not biologist]) I'm at a bit of a loss to explain exactly why I am succeeding when I should be failing.
As always, any inspiration is most welcome!
What about the quantity of the feeding? Say you triple the volume each time, the organisms need that much more time to go through it all. So, if it is only doubled maybe twice a day is necessary, but if it tripled, it can survive 24hrs.
My kitchen is not heated and so in winter, it goes down to 18°C and in the day, never over 19-20°C. These few degrees make a huge difference. In the heat of the summer, the kitchen can go up to 27°C, but usually 25°C very easily and the starter actually foams. I have to feed it three times if left out. I think it is the metabolic rate that is so fast, thin bubbles for, while in winter, the bubbles are thicker.
OK, I'm just throwing out a bunch of ideas.
Jane
That's what this experiment was designed to test. And yet, I saw no difference.
Perhaps "my critters" are particularly adapted to their less than easy life...
Or perhaps the once-a-day feeding dilution has still not yet reached the threshhold where the culture will eventually be diluted out to oblivion (despite what some may claim).
SteveB
www.breadcetera.com
My alternate theory is that since I am "eyeballing" my feedings that I make adjustments of which I am not aware (feeding more, taking out more levain) and this keeps the thing healthy.
I've really been doing this for a number of years. So it's proving to be sturdy enough.
When I am ble to spend more time on indoor things I may try the twice a day feedings again to see if I am getting any value from them.
Until then...
Happy Baking!
Of course that it a big factor! The other day, I tried to explain to someone how to make gluten-free bread. It is so easy, that I didn't think it would be a big deal... but then I had to get in to feeding the starter, how much, when, where to put it, the consistency it should be even before trying to explain the actual bread making process. I realized then how unscientific I was (I don't think they ever made the bread and I still make it for them). So, I think that over time, small adjustments are made and we don't really register them. Like when I would make my basic sourdough, I noticed that the dough was better if I filled the cup of water up fuller (without actually measuring), but never actually mentioned that in my recipe, so I was putting probably 340ml instead of 300ml, but without even registering! So, you have probably noticed little things about your starter and accounted for them without ever really registering in a scientific manner.
Jane
Pat,
You really put those critters through some gruesome workouts. Thanks for the interesting write-up. Rainy days are good for bread making projects. I've been out of the loop on summer activities, but I enjoyed reading your entry and the discussion.
I've spent a lot of time experimenting with my starter trying to understand how fast it grows under various conditions. It's interesting to try to model your situation, although I didn't focus on 50F temps much along the way in my modeling process.
The first thing that occurs to me is that at 50F, you probably would want to use a very low feeding ratio, since the stuff is going to grow very, very slowly. For example, it looks like if you replace half of your starter, then at 50F, my models would predict you would just about double the population, i.e. get back to the same population density you started with before the feeding in about 24 hours. So, the low feeding ratio seems right for the time it spends in the special refrig Sunday through Thursday.
However, my models would also predict that if you feed 1:5:5, then 24 hours wouldn't be enough at 50F to get back to the pre-feeding population density, although you might get up around 25-50% of the pre-feed population density in 24 hours. That would mean that eventually you might dilute the culture if you kept on going at 50F every 24 hours at 1:5:5 for a long time. If the temperature were only 5 degs higher, i.e. 55F, there would be just enough growth to keep the population stable. If you had two hours at 75F, and 22 hours at 50F that would also be enough to get the population back up, so if you are using warm feeding ingredients and leaving it out for a little while during the feeding process, maybe that would explain how 1:5:5 could live long term in the conditions that prevail Sunday through Thursday. Again this is just in my WAG models which are cobbled together from doing a zillion different risings at various inoculations, hydrations, temperatures, and so on, plus a bunch of assumptions and extrapolations and using some data here and there from scientific papers on the behavior of the typical yeast and lbs. Lots of slop in the analysis, obviously.
For the Friday-Saturday part of the routine, maybe that's when the 1:5:5 starter fully recovers, since 24 hours should work well for a 1:5:5 routine at room temperature. For example, at 70F, you would expect the population density to replace itself in 8 hours. In the next few hours, it would double enough times to more than make up for a few days of 25-50% dilution per day. At the same time, I would think that "Thing One" might suffer a little if sitting at room temps for 24 hours with less than a doubling feeding ratio. However, it's only for two 24 hour cycles, so it should still be fine, especially if the temperatures are mostly at the cool end of room temperatures. I would bet that at the end of the 24 hour cycle at room temperature, Thing One has begun to have a declining population count, though, unless you are giving Thing One higher feeding ratios on Friday and Saturday, which maybe you would do as part of the build-up to bread making.
I still wonder if you have L. pontis instead of L. sf or similar in Thing One, since the pH should be chronically so much lower than what prevails when you do higher ratio feedings at firm consistencies, but I sure don't know enough biology to design a test to tell the difference. It would be interesting to find that out someday, if you discover a microbiology expert with a lab who could identify the organisms.
By the way, when you measured the pH of the two starters above, that was after both had time to ripen? If so, then I understand the pH being around 3.5, which is consistent for ripe cultures, regardless of what ratio you fed them with initially. However, if you are saying that immediately after feeding, the pH of both was 3.5, I'm baffled. I've done measurements of starters over time from right after feeding until they are ripe, and the pH ought to be much higher immediately after feeding for the 1:5:5 ratio (like 5.5 or so) than for a low feeding ratio as in Thing One. You have both the buffering effect of the flour and the dilution of the acid acting to raise the pH after the 1:5:5 feeding.
Bill
Bill,
It's nice to see you around again and read your scientific starter point of view.
Jane
Hi Jane,
I hope to be around more in the fall - summer is my outdoor busy time, but I couldn't resist checking in with Pat on his Thing One and Thing Two experiment. It's nice to see you are continuing to contribute here on TFL.
Bill
Thing One - with a low feeding ratio looks a little sorry after spending Sun-Thur in the 50F refrigerator and Thing Two does also, but not so much so. Both are definitely past their peak when I remove them, so low or high feeding ratio, they are both digesting pretty much all the food they are provided. Although if I fed every day Thing Two would dilute - they don't get fed Sun-Thur, so it makes sense that I'm not seeing dilution.
On Thursday evenings I feed them both. I remove a small amount from whichever levain I am using to do my build for baking, so neither gets a different feeding. By Friday evening the bread must be baked, so there is no room for coddling the levain. It comes out of the refrigerator and better be ready for bread making in 6-10 hours (depending on the lateness of my homebound flight). Thing One has lived with this routine for years, so one speculates about the process of natural selection that went on. I did have trouble with this levain when I was first using it (years ago) but at the time wrote it off to bad baking technique. I wonder, though, if I wasn't experiencing a shakeout in the population of the levain.
Both double in 8 hours or so (I'll watch more closely this weekend) at basement temperature - which is around 70-75 degrees - or in winter room temperature which is 60-65 degrees. I do bulk ferments for my doughs at about 75F and I get a double in 2 hours pretty reliably
I took the pH when they were fully ripe, which oddly enough happens at about the same time. After feeding, you are right, the pH of Thing Two is higher. A while back we were speculating that if I had l. pontis, there would be greater acidity in the culture and that if I changed the feeding ratio, the L. sf might start to predominate. I was trying to figure out best time to take the pH so that I would have a reasonable comparison. Perhaps whatever I have is so dominant that even a drastic change in the feeding ratio is not going to knock it out. Alas, finding out just what is in there is not so simple as sending flour to a lab. I'm trying to work up some contacts at a university - but this is not my field...
While researching how I might determine what is in the levain, I did find works that suggest that there are a number of the lactobacillus family that are good for bread making and also that these do mutate.
I will try some additional pH readings at other times and see what's up with that.
Over the next couple of weeks, I will actually be at home and should be feeding my levain daily (no refrigeration). I may even try twice daily feedings just to see if this widely accepted practice does any good for my levain.
Later...
Pat,
I see how it works during the week now. It does make sense that Thing Two looks fresher on Thursday. It would spend longer in a growth phase, although a slow growth phase, at 50F, probabliy peaking on Monday or Tuesday and then beginning to decline after that. Whereas Thing One would probably peak in 24 hours and fall off Monday through Thursday, ending up less fresh looking than Thing Two. However, since the decline would be very slow at 50F, a few days won't make a huge difference between how the two recover from Thursday through Sunday.
Now I'm still confused about the process Thursday through Sunday, and I'm probably asking you to repeat something you've already explained, so sorry about that. However, what is the feeding routine for the Thursday through Sunday part of the routine?
If I understood correctly, the starter is also the levain. In other words, you just take out the whole starter less a small piece to propagate for next time, whatever that is, feed it, and let it rise for 8 hours, at which time it has generally doubled and you use it in your dough?
At the same time, are you separately rebuilding a starter/levain that will be put in the special refrigerator on Sunday? Is this when Thing One and Thing Two are fed differently, or is there a one-time feeding on Sunday that is different?
Just a comment on the twice per day feedings idea being a good practice (or not). I believe there are 2 main factors that determine how often you should feed the starter, feeding ratio and temperature. For example, I think we would both agree that twice per day 1:5:5 feedings at 50F would dilute the culture and at some point would wipe it out. However, I've done twice per day feedings at 1:4:5 in the summer when the temperature was running about 78F-79F, and it worked well. If I were to feed only once per day at 1:4:5 at 79F, it would be fine, too. However, the starter would be very liquidy, acidic, and possibly start to smell of acetone at the end of 24 hours in those conditions. At 68F, a 1:4:5 feeding every 24 hours is better. Twice per day would work but not allow the starter to fully peak and ripen. I think it makes sense to let the starter ripen for a while after it has peaked, since the yeast should continue to grow after the pH has dropped below 4, allowing it to catch up, since it generally grows a little more slowly than the LB but can continue to grow at low pH after the LB quits growing.
So, what I'm getting at is that you can design a zillion different routines that will work. You just have to meet certain basic requirements: 1) It has to grow for long enough at whatever temperature and feeding ratio you choose to fully replace itself. 2) It should be stored for a period of time that, while it certainly declines in population, it doesn't completely die out. 3) The recovery/refreshment/coddling process should be designed to fully replace and stabilize the culture, taking into account the extent of the decline caused by the storage period. Your process appears to accomplish all three conditions above very well, so that it works very well, but as I said before I would love to know if the chronically low pH of Thing One results in some different organisms than mine might have maintained at 1:4:5, every 24 hours, i.e. spending much more time at pH above 5 than your Thing One would. So, if we discover someone who would identify the organisms in our cultures, maybe we could both send a sample in.
It seems to me that starters can last quite a while in a declining state, and that decline is far more rapid in warm temperatures than in cool temperatures. However, I've had a hard time finding any real scientific studies detailing the declining phase of a starter as a function of temperature. However, even at room temperature, you can let a fully ripe culture sit for a couple of days at least, as I have done that and seen the culture change from firm to liquid consistency and extremely sour and develop some off smells, like acetone, but then recover quickly if fed a time or two.
I've had more experience with refrigerating my starter for storage. An extreme example has been that after storing a culture in the refrigerator at a very firm consistency, having fed it 1:2:3 or so just before refrigerating, it would last 6 months, and be pretty much the same as ever after about 48 hours of "coddling" or "refreshing", i.e. feeding 1:4:5 every 12 hours at about 80F. That would seem to imply that the decline is very, very slow at 40F, since 2 days of rapid growth at room temperature seems to make up for 180 days of decline at 40F in the refrigerator. That would imply that the starter declines at around 0.5% an hour in the refrigerator at 40F over 6 months, if it can recover growing at around 50% an hour or so at 80F in 2 days.
Bill
All of what I call my levain lives permanently in their little plastic tubs. If I want to bake - I take a certain weight from the plastic tub, put in in a bowl (or something) and feed it with flour/water to form the preferment for my bread (and I usually do this at the levain being 25% of the total weight of the preferment and the preferment being 12% of my total flour). This is expected to raise bread to be ready for baking by late afternoon on Friday (which is does - pretty reliably)
Sunday afternoon through Thursday evening or so, the tubs live in the 50F fridge.
Thurs evening I will do a "build" as described above for my weeks baking. I will then turn to feeding the levain in the tubs.
From the tubs where it lives, I will then remove either "about half" for Thing One (which leaves about 4- 5 oz in the tub) or "all but about an ounce" for Thing Two.
Both are then fed with 4 oz each of flour and water. A 1??:1:1 ratio for Thing One and about a 1:5:5 ratio for Thing Two.
I repeat this Friday evening, Saturday evening and Sunday morning - before stashing then in the 50F fridge to start another cycle.
In warm weather, they spend Thur eve to Sunday morning in the basement - which will be at the absolute most 75F. In winter, they are in a cool room of the house (just easier not to keep running down to the basement) which would be around 65F.
Hope that is clear. It has become such a routine for me that I probably don't describe it well.
Having different organisms because of different feeding styles was something we were discussing way back in the Spring - so I decided to try the different routines for a while.
I've seen both the "Things" look past their prime, but I have never gotten the acetone smell you describe. And I don't like sour breads so I never really get strong sour tastes in my bread. Wonder if that is connected? I need to read up on that.
What I might try is reading the pH at several points - after each is fed - 1 hour - 2 hour - peak - one hour after peak - etc. and see how long the differential in pH is maintained. I also have the opportunity over the next week (when I am not traveling, for a change) to observe my "Things" more closely and see when they double and collapse and I will do that and do a timeline. You would think that I would see a difference between the 1:1:1 and the 1:5:5. You would think, but I am not at all sure from my more casual observations that I have.
My critters - what an interesting life...
If I find someone willing to do an analysis - I will let you know. That would be the most interesting thing of all...
Very interesting, all of this!
Just wanted to say that Bill told me a while back that he had kept a starter in the fridge for months and it came back to life. So, I did some experimenting. I put a liquid starter in a tightly closed jar and hid it in the back of my fridge. All the knowledge I had at the time told me it should die.
I left it for a very long time (OK, not six months but at least a couple) and after a few feeds it was back to life! It was stored at about 5°C. It had a very dark, thick hooch.
They are very hardy critters indeed!
Jane
Yes I'm more convinced than ever that I know nothing about nothing.
Got home from the Ark-La-Tex 18 hours later than usual, but set about tending my levain and taking readings.
After Sun-Friday in the fridge. Thing One was looking ragged. A little clear hooch, but no acetone smell (to my nose). Thing Two was definitely past its peak (but no hooch). pH of each 3.5
I then fed them both following the method in an earlier post. Immediately after feeding ph Thing One 4.0 and pH Thing Two 4.5. One would expect a somewhat biger difference, but, there you are.
After an hour at 75F, Thing One had doubled and showed a pH of 4.0. Thing Two was not quite doubled (but definitely close) and had a pH of 4.0
After three hours Thing One had tripled and had a pH of 3.5. Thing Two had doubled and had a pH of 4.0
At which point, I did a build from Thing One and determined that as I had been up since 4AM, maybe I needed to record my stuff and get some shuteye.
Remember, I have been feeding Thing One at a 1:1:1 (or so) ratio its entire life. Thing Two has been fed at1:5:5 since May. I guess I would have expected a bigger pH difference than .5 - I mean .5 is measurable (just barely) but for most organizms with whom I have been acquainted, not anything that would make the difference between viability and not.
Thing One has spent years with the power to double in an hour at 75F - but yet is fed only once a day.
Which takes me back to my point that according to the "experts" Thing One should be dead. But it is not.
And fed at two wildly different ratios - the "Things" double in nearly the same amount of time. This is not intuitive.
Did its tough life cause some balance to develop that cannot be upset in the levain. Is it L. pontis? Is one Lactobacillus so dominant that nothing can dislodge it? Do I just have wild yeasts?
As I said before, I am ever more convinced that I know nothing about nothing.
Whatever I've got in there, it has quite a will to live and reproduce...
Is there a Doctor of Micro-biology in the house?
Happy Baking!
Pat,
In my favorite paper on this subject, by Markus J. Brandt, Walter P. Hammes, and Michael G. Ganzle,
"Effects of process parameters on growth and metabolism of Lactobacillus sanfranciscensis and Candida humilis during rye sourdough fermentation"
(Eur Food Res Technol (2004) 218:333–338)
they show that growth of L. sf drops off precipitously from pH of 4.5 down to pH of 4.0. So, I believe it will make a big difference to the well-being of any L. sf in Thing Two (if any is in there) if it is fed so that the initial pH starts at 4.5, as the growth rate of L. sf during those few hours the pH is above 4.0 will far exceed the growth rate of any L. sf in Thing One that is already at 4.0 right after feeding.
I notice that the paper matches inoculum percentage with pH, and it does appear they expect an inoculum of 5% (more like 1:10:10 feeding ratio) to be the same as a pH of 5.0. This was in a rye culture, and rye flour probably has a higher buffering capacity, as it probably has a higher ash content than a white flour would.
Now that I think back, my pH of 5.5 mentioned earlier wasn't after feeding an ongoing culture, but instead was during culture startups I was doing using ascorbic acid doctored water at pH of 3.5, which was then mixed with flour to create a 90% hydration starter. That is what had a pH of 5.5 after adding the flour, which I guess isn't really exactly the same as starting with a 100% hydration ripe culture at a pH of 3.5. I'll have to measure my pH after feeding when I get home to NJ and get all this stuff started up again.
I don't know what all is going on either, but I do think there is a big difference to L. sf, based on what this paper says, between starting with a pH of 4.5 or 4.0 in the feeding routine. Also, the paper says that it is common for starters maintained at high acidity, i.e. low feeding ratio, to have a higher ratio of yeast to LB cell counts. I think this is the same paper where the mention of L. pontis being a common inhabitant of higher acidity cultures appears because L. pontis is more tolerant of low pH. What any of this means to the flavor of your bread, I don't know nothing about nothing, either.
By the way, there is a lot of discussion in another thread about sour flavor, and I believe this is very true - that the main effect on the intensity of sour flavor is just how long you allow the fermentation to progress, as this will determine the total acid content, which is correlated with intensity of sour flavor. In particular, for the fermentation to last longer, you need more buffering effect from the flour to slow the drop in pH (which is what will stop the LB from continuing to be active), which you will get with higher ash content flour and a firmer consistency of dough, combined with enough time to allow the fermentation to progress as far as it can without having the dough "go to rags" or develop off flavors. But that's a whole other story.
Bill
Bill,
So , since I have a culture that has been maintained for years at a low pH, it may be that the L. pontis is so dominant that I will never see L. sf.
The predominance of wild yeast also is consistent with the rapidity at which both the "Things" double and the rate at which my bread rises.
See, I knew you'd have some inspiration for me...
What does it do for the taste of the bread. Well, my bread is never very sour and frankly that's how I like it. It is definitely different from bread made with commercial yeast, but I have had a lot of opportunities to eat San Francisco sourdough and I - er - don't really like it that much.
So maybe that bad stretch of baking years back was the shakeout of organizms and the levain became very stable with they L. pontis who actually enjoy my feeding routine. Since I was and am happy with the taste of my bread I didn't seek to change anything and it became more entrenched over the years.
I would be interested to find out your pH readings and will be taking the opportunity in the near future to get readings on other cultures.
So I think I'll stop beating myself over the head with what "common wisdom" tells me I should do. I'm happy and the critters are happy - could I ask for more?