The Fresh Loaf

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What happens if I mix different sourdough cultures together?

Ispahan's picture

What happens if I mix different sourdough cultures together?

I have tried searching for an answer here on the forum, but I have not yet found a satisfactory answer.  What would happen if I mix together three different sourdough starters that I have and combine them to make one culture?  Would I have a hybrid culture, or would would the strongest of the three simply take over and outgrow the other two?  I have the starters from KAF, Breadtopia and a San Francisco culture from Cultures for Health, but I don't use either of them enough to justify keeping and maintaining three separate starters.  I have no preference for any of the three cultures I have, since all seem to produce wonderful, tasty bread with great rising ability.  

Thanks in advance for any advice, help or comments.

gaaarp's picture

You would, at first, have a hybrid culture. Over time, your local airborn yeast will take over all three of them, individually or mixed. So there's really no reason to keep all three, especially if you don't use them much.

Another alternative would be to dry two of them and just keep the third active. To do this, feed them up, then when they are nice and bubbly, spread a thin layer of starter on a Silpat or parchment paper and let it dry. Then crumble it up and keep it in an airtight container. It will keep this way indefinitely.

If your starters are young and still have their own distinct flavors, it might be worth drying some of each. If you've had them around for a while, they are all pretty much the same, so mixing them is fine.

LindyD's picture

Mix them up, refresh the culture a few times, and you'll have a good, active sourdough culture that tastes like the wild yeasts present in the flour you use, and your environment.  It will produce the same wonderful tasting bread you've been making.

James MacGuire noted that each time he has been given a piece of a culture, regardless of whether it was 100 years old or came from a different region, within a few days of his usual maintenance it produced bread that tasted exactly like the bread produced by his own culture.

dennisinponca's picture

Not much of an answr here but my guess is you might create a hybred but eventually the strongest yeast will eventually over power the rest.  It may be a matter of luck if you end up with a hybred that tastes better.

I am of the opinion that every time you expose your starter to the air, you take a chance of contamination and that contamination may improve or may ruin you original starter.

I suggest you keep some original back  and experiment to your heart's content.

I like to use wine yeasts with my sourdough breads but I am always careful to keep my original as pure as possible.  The wine yeasts have provided a bit of flavor but nothing to really get excited about (so far).



jeremiahwasabullfrog's picture

With bacteria and yeasts it is too complex to give a blanket answer - including that local yeasts will take over. Well, maybe, but maybe not, it depends which is better adapted to living in your sourdough culture. If there is significant new genetic information in your culture, it is even possible that they will colonise and take over the local wild yeasts :) but not very likely.

Bacteria adapt to very specific environments, and your sourdough culture is a very different environment to the local wheat field/ flour mill/ vineyard. SO what is adapted to live there might not be the strong guy in your kitchen.

Another factor is that your culture is a community. The yeasts you have are adapted to live in the environment created by the lactic bacteria and vice versa. The local yeasts might not get on with your lactic bacteria. Evidence shows that this tight community is very hard for other organisms to colonise, that's why they are so stable.

I know I have kept cultures (both made from local yeasts) with very different properties, and they have stayed different.

So to answer the original question, if you mix them, who knows what will happen. Because bacteria can actually exchange genetic information, there will be hybridisation which may create new strains if there is an advantage for the bacteria/yeasts. Or they just might not like each other :)

Impossible to tell without trying - give it a whirl!


as an addenum, I think the most powerful way to get a "different" culture is to change the balance of organisms. Frequent feeding will mean more yeasts, less sour, and less frequent feeding means more sour. Same community, different balance.


chatelaine's picture

I did just that by mistake.  I used the same whisk to mix two different cultures.  The first time one batch simply ceased to bubble and work away.  It stays smelling yeast but is sulking profoundly and has done for 3 weeks now.  I keep feeding it and await life.  The second time was a mistake and I ruined my four year old self made and most robust sourdough culture.  It has small signs of life but I think it will take considerable time to resurrect it.  So, perhaps, my advice would be: don't.

gerhard's picture

I would have never thunk it.  The two cultures must have fought and no one survived to tell the story.


dabrownman's picture

everywhere is to remove the fear of opening your SD container because you are afraid that that it will be contaminated by local yeast and LAB in the air that might take over the culture.  Or, for that matter, the idea that SD cultures are colonized initially by local yeast and LAB in the air.  If we could get rid if these myths SD folks could lead much more productive and happy lives.  I say throw off that yolk of folklore and move on to 

Happyand  Worry Free SD Baking

doughooker's picture

I agree with dabrownman. The strains/species of wild yeast and lactobacilli in sourodugh cultures are found the world over, from San Francisco, Poland, Austria, The Yukon, Saudi Arabia, etc. The current thinking is that they settle on the grain in the field and are to some extent picked up in the milling process. You would have to know where your grain was grown and milled in order to have a geographic identification.

Note that the web site selling starters from diverse regions does not identify the species or strains, but merely gives a geographic location. For all we know they are all the same strain/species no matter their geographic origin. The notion of geographic specificity is mythology which gets perpetuated ad infinitum on the Internet.

Go ahead and open your starter jars. The same microorganisms that colonized it in Dublin, Ireland will be the same ones that will colonize it in Houston, Texas.

baybakin's picture

"The notion of geographic specificity is mythology which gets perpetuated ad infinitum on the Internet"

See, I beg to disagree on this, there has been a large quantity of research (especially in the wine industry) that shows that indeed microflora and fauna such as yeast/bacteria varies greatly in different localities.  This is not a point of debate. However, starters will certainly change no matter what, to whatever yeast/bacteria you are inoculating every time you add flour, and in the methods that you maintain your culture.  So the selling of "geographical" cultures muddies the waters, and misleads consumers, not because they are all the same (they are not), but because they will all change and adapt to your feeding/maintaince schedule no matter the geographical origin of the original culture.