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2019-06-30 - Another delicate matter....

Or, Everything you know is wrong!

Or, is it?

That was the title of one of my favorite Firesign Theatre records. Remember records? Remember sitting around the stereo? Ahhh.. memories... anyway, let's talk about some sourdough beliefs and misbeliefs!

There seem to be two major camps in the sourdough community. Some people chart and track the care and feeding of their starters with obsessive and scientific precision. The heavens will tremble if they feed their starters 5 minutes late!

I saw one post in the "Perfect Sourdough" Facebook group where the writer was tied up in knots. He was in day 5 of starting a starter and he forgot to discard half of his starter. Should he start over? (I'm surprised no one suggested he should just shoot himself.)

There is similar obsessiveness about the use of metal with sourdough. One person wrote me years ago - she'd inadvertently stirred her starter with a stainless steel spoon and threw the starter away because she just knew she'd ruined it. Spoiler alert - I've talked about this at length in our "Sourdough Myths and Folklore" page.)

These folks will often tell you that their way is the only way to handle a starter, or sourdough. And they have exacting ways to do everything.

And then there are the people who are far more laid back. They happily tell you they just let their starter sit on the counter until they need it. Then they feed it once and it surges back to life! Regular feedings are for the birds!

Or maybe they leave it in the fridge, maybe feeding it once a month. Pulling it out to feed it once and then use it. Again, it always springs back to glorious life!

They don't understand why the more cautious group is such a bunch of obsessive nitwits.

And the obsessive nitwits view the slapdash antics of the careless guys with something akin to horror. It seems like cruelty to not feed a starter!

OK, I may have taken some poetic license in describing both camps and added a touch of melodrama. But probably not a lot of melodrama.

As usual, I tend to think the truth lies between the extremes. Have you ever skipped a meal? Or forgotten to feed your dog? Somehow, you - and your dog - managed to survive the horrors of starvation. Sourdough isn't as finicky as many people want to make it seem. As we recently said, "remember to breathe!"

While starter is more resilient than many people think, that doesn't mean that it's advisable to just ignore it, whether on a counter top or in the back of the fridge. We tend to think if sourdough as being a symbiosis of one yeast and one sourdough bacteria. And that seems to not be the case. Even the more relaxed notion that most cultures have A yeast and A bacteria that are dominant by orders of magnitude may not be all that accurate.

We look at the evolution of sourdough and understand that there is a succession of organisms. We tend to think that the Pediococcus bacteria that start a starter "go away," as do the leuconstoc bacteria that appear in the second stage when they give way to the real lactobacillus bacteria. We know that each succeeding wave of bacteria made the environment too acidic and too toxic for it to continue to survive, and we know that sourdough bacteria has a large arsenal of tools to wipe out competing organisms. Darwin's "Survival of the fittest" writ small, as it were.

So, I was really interested when David Auerbach, a sourdough and Facebook friend, told me that he'd sent his starter to The Sourdough Project" at The Public Science Lab. It got more interesting when David told me he'd given some of his starter to a friend about 20 years ago and his friend had sent that starter in as well. So many questions popped up. How different were the starters? What were the critters in the starter? How high is up? How sour is sour? So, I spent some time looking at the test results on his starter, and the forked starter.

Here's what was found....

David Auerbach, starter 867 Starter 742 -
20 year fork of David's starter 867
Yeast notes:

* Taxa highlighted in red are common (found in at least 100 samples)

* Any taxa highlighted in teal are rare (found in 5 or fewer samples)

Yeast Taxa Percentage Yeast Taxa Percentage
Saccharomyces cerevisiae (strain 2) 49.62% Saccharomyces cerevisiae (strain 2) 53.90%
Saccharomyces cerevisiae (strain 1) 44.64% Saccharomyces cerevisiae (strain 1) 45.48%
Candida sp. (strain 2) 3.11% Wickerhamomyces anomalus (strain 2) 0.18%
Candida sp. (strain 1) 2.03% Candida quercitrusa 0.16%
Wickerhamomyces anomalus (strain 1) 0.33% Wickerhamomyces anomalus(strain 1) 0.10%
Kazachstania humilis (strain 4) 0.07% Meyerozyma guilliermondii 0.05%
Candida glaebosa 0.07% Candida sp. (strain 1) 0.05%
Wickerhamomyces anomalus (strain 2) 0.03% Kazachstania wufongensis 0.04%
Hanseniaspora uvarum (strain 4) 0.03% Hanseniaspora uvarum (strain 4) 0.02%
Kazachstania humilis (strain 3) 0.02% Kazachstania bulderi (strain 1) 0.01%
Wickerhamomyces anomalus (strain 3) 0.02% Debaryomyces hansenii (strain 1) 0.01%
Kazachstania wufongensis 0.02% Kazachstania servazzii (strain 2) 0.01%
Kluyveromyces marxianus 0.02%
Bacteria notes

*Taxa highlighted in teal are Obligate heterofermentive

*Taxa highlighted in lime are facultative heterofermentive

*Taxa highlighted in purple are Obligate homofermentive

*Taxa highlighted in red are likely Obligate homofermentive

Bacteria Taxa Percentage Bacteria Taxa Percentage
Lactobacillus sp.7 99.62% Lactobacillus sp.7 99.65%
Lactobacillus brevis strain 1 0.14% Lactobacillus brevis strain 1 0.08%
Lactobacillaceae sp.7 0 .08% Lactobacillus plantarum 0.05%
Lactobacillaceae sp.1 0.05% Lactobacillaceae sp.7 0.05%
Lactobacillaceae sp.3 0.03% Lactobacillaceae sp.1 0.04%
Pediococcus sp.1 0.02% Lactobacillaceae sp.3 0.04%
Lactobacillus paralimentarius 0.01% Lactobacillus paralimentarius 0.03%
Lactobacillus plantarum 0.01% Lactobacillus brevis strain3 0.02%
Lactobacillus zeae strain1 0.01% Pediococcus sp.1 0.02%
Pediococcus ethanolidurans strain1 0.01% Lactobacillus sp.2 0.01%
Lactobacillaceae sp.2 0.01% Pediococcus sp.2 0.01%
Lactobacillaceae sp.5 0.01%
Leuconostoc sp.1 0.01%

David and I were surprised at how very similar the two starters were after 20 years. It's like a magazine article about separated identical twins who are so much alike, they even use the same obscure brand of toothpaste!

While the folk wisdom that a starter will have a yeast and a bacteria dominant was largely true, two yeasts were pretty much equally represented. Both are strains of Saccharomyces cerevisiae which are probably very simular. It was surprising how many other organisms were in the starters. Even the Pediococcus and Leuconostoc that I'd assumed would be gone. Sure. it was .02 and .01%, but they were there. And when you're dealing with hundreds of millions of organisms in a cubic inch, that's a lot of those organisms that seem so insignificant. Some biologists tell us that there are Neanderthals walking among us, and suddenly I think it could be true.

I'm still digesting this informtion and may talk about it again. But for now, it;s worth mentioning that the somewhat contentious Modernist Cuisine has a good article about sourdough starters. They talk about the stability of starters and conclude, "But locking in a specific population of bacteria is not important. What matters is creating a hearty colony of yeasts and lactic acid bacteria that behaves predictably; in other words, as long as the levain is fed on the same schedule and kept at about the same temperature and hydration, it will ripen and mature as expected."

But for now, I am more convinced that starters are relatively stable, and that they don't change because you move. I talk about this on the Sourdough Myth's page.

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