September 25, 2014 - 3:30pm
wild yeast
hey all
i have a more advanced subject question. i want to know. I went on vacation recently to Ukraine to visit my wife's family and i decided that i would collect some wild yeast. so i set out to collect it and i was successful. now I have a wonderful new born yeast culture and im back in America...so here is the question that maybe you can already see coming...but i desperately need some literature on the subject. will the Ukrainian strain/s of yeast in the sourdough culture prove to keep repopulating as the same Ukrainian strain...or will the local strain/s take over eventually...
Thanks
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I doubt there is a species/strain of yeast indigenous to Ukraine that isn't present elsewhere in the world.
A yeast culture is like a neighborhood. Some are native to the area, some move in, sometimes whole families move in and take over. Eventually, some move away, others move in and so it goes. Sometimes big families stay in the area a long time-thriving and reproducing. Some families are smaller or weaker and go away faster. That is how your yeast from home culture will be. It can be replenished with yeast from home if you can get some flour grown and milled in the Ukraine because that is where your yeast originally came from.
Have fun!
I don't know much about yeast strains but are there geography-specific strains of yeast that occur only in certain parts of the world and not others? Wouldn't it be reflected in the name if it came from Asia, Africa, South America, wherever? This is a long-standing question I've had about Dr. Wood's starters. How is S.cerevisiae from Egypt different from S.cerevisiae from Hong Kong? Do they obey political boundaries? Do they send fighter planes if the yeast invades enemy territory?
Some cultures are more stable than others. The culture that I am most familiar with is quite stable. It is stable over time and also geographic separation. From the comments I have read here and elsewhere over the years, others are not.
I think that the best way to preserve the desirable qualities of a culture is to keep the culture healthy with regular feedings and feed, at least your "Mother " culture with ordinary white flour. White flour generally has fewer yeast and bacteria critters than whole grain.
Eventually the culture organisms that thrive the best in a given environment will become dominate. However, if you start with a stable, healthy culture and feed it with flour that has a small load of culture type organisms, the current dominate organisms may never be replaced.
Charles
And since most flour one buys is rarely from grain grown next door you probably already have yeast from around the world.
alright cool its a good start...my problem with this topic is that there seems to be no one that can provide actual accounts... as far as the difference in yeast between different countries...there should be a difference in character....S.cerevisiae although is the same in Egypt as in Hong Kong...the character should be different....a simple example is the difference between Egyptian humans and Hong Kong humans....same organism...different characteristics. Thats my theory at least....the problem with it is that i don't have any actual proof to back it up...but i agree that feeding it with a local flour...maybe even giving it some shots of whole grain or rye flour to populate the culture with the local yeast desired would be ideal...we will see what happens in the time to come
Thanks for all the responses and if anyone has some links to some scientific or just proven accounts or some old world bakers want to chime in on the subject the more knowledge the better for me
A number of years ago, I bought a small canister of Sourdough Jack dried starter that was from the 1960's. It was a dusty,dirty container that still had the original tag (without a barcode), the original label and the original cellophane packet of dried sourdough starter inside. Could it possibly be still viable? It was. I activated it and used it deliciously since then. I notice that it always has a rather unique smell and flavor from my other starters. It is always active and easy to re-activate after a rest period.
That was about 4 years ago.Usually, over time, my other starters start smelling and tasting like Jack, so I think he gets around. He seems to be a particularly healthy specimen and good at what he does. He may have come from San Fran but he has always been fed a brand name (Pillsbury,Gold Medal) AP flour and thrived in Wisconsin,USA. So maybe it is like people-some are stronger and healthier than others but we are all homo sapiens.
Simple and straight answer here. Your culture will eventually be taken over by the microorganisms present in your current location.
I am with Mixinator on this one, and a fan of "yeast without boarders"
I don't know why you are desperate for literature, but you can read a lot about sourdough on the internet, including lots of published papers.
One thing I would caution you on, tongue in cheek, is that your yeast is no longer wild when you raise it in a jar. Perhaps its ancestors were wild but by the first few feedings you have domesticated the yeast, which is as it should be, since it is doing your bidding and no longer living the care free life it once lived.
And, in all seriousness, tongue in cheek, the life of a wild yeast is overly romanticized. It is a life of constant struggle, dormancy and struggle for food and reproduction. It is much better to live in a jar and be fed regularly.
Nicely put and well explained.
I'm not on board with this "character" theory. If there were a discernable difference it would be documented by microbiologists. Otherwise I chalk it up to superstition.
Are you saying that you think there are only a few strains of yeast or bacteria found in our starters?
in Saccharomyces cerevisiae alone, there's a study that analysed 651 strains from 56 different geographical origins worldwide, finding 575 distinct genotypes. Furthermore "28% of genetic diversity between these technological groups was associated with geographical differences which suggests local domestications." If you look at the types of yeasts that are on flour, you get a list much longer, most probably with similar genetic diversity. (In one study of yeasts in italian sourdoughs and flour "58 strains were identified as Saccharomyces cerevisiae, five as Candida colliculosa, four as C. lambica, three as C. krusei, three as C. valida and two as C. glabrata.")
So I'd say there is plenty of proof that yeasts are localized, and I see no reason why bacteria would be any different.
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-294X.2007.03266.x/abstract;jsessionid=13F7D89A489FE215E658C26B5AAB7139.f02t03?deniedAccessCustomisedMessage=&userIsAuthenticated=false (on localized yeasts)
http://onlinelibrary.wiley.com/doi/10.1016/S0378-1097(03)00500-7/full (yeasts found on italian sourdoughs and flour)
My culture has not permanently changed its basic character in over 20 years. I feed the "mother Culture" with the cheapest AP flour that is on sale or any of my stock that is outdated. That would include all the national brands and several store brands available here.
How would "local" organisms get into my culture anyway? They are not likely to come with the city water that comes from deep wells and is chlorinated or my alternate source of bottled water.
The only time my culture is uncovered is when I am feeding it or taking some out to build up a levain. The odds that some dust mote carrying a disruptive sourdough culture critter finding its way into the jar in such a small time window are almost impossible.
Of course sourdough critters (and others) are going to come in with the feeding flour. The odds of introduced organisms being better adapted to the environment of your culture than the ones already thriving there are small. And, unless you have a local miller using local wheat, the introduced creatures won't be "local" anyway.
If you keep a healthy culture and feed it with flour that has a low load of microorganisms, you have a good chance of maintaining a stable culture.
Sourdough cultures will change in response to a change in the environment. My culture behaves somewhat differently in the Winter when it lives on the counter and is fed two or three times a day compared to the summer when it lives in the refrigerator and is fed once a week. It is stable because when it returns to the counter this winter, it will acquire the same behavior it had last winter living on the counter.
My opinion is that at least some of the reports of a culture being taken over by "local" wild yeasts is merely the observation of a culture responding to changed environment such as a change in feeding frequency, temperature, hydration or different recipes being used.
Interesting about the localized yeasts.
I keep my starter sealed in the fridge, so the local yeast don't have much chance to infiltrate. Different yeast likely wouldn't change the flavor anyway.
I would think the bugs in the wheat field and mill would play a more significant role, but that's just a hunch.