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Why Do People Care for Sourdough?

Using one family’s story and survey responses from hundreds of Sourdough Project participants, Matthew Booker will speculate about why people carry sourdough cultures with them around the world and down through generations.

Published onApr 23, 2020
Why Do People Care for Sourdough?

Editors note: This publication contains the video of the talk from the Fermentology webinar series, as well as a lightly edited transcript of the lecture.


Using one family’s story and survey responses from hundreds of Sourdough Project participants, Matthew Booker will speculate about why people carry sourdough cultures with them around the world and down through generations. Maintaining sourdough in our kitchens pairs human and microbial cultures in a multispecies community with intriguing implications for both human history and biological diversity. Matthew is an environmental and food historian and soon to be the Vice President of the National Humanities Center. See his books Down by the Bay: San Francisco’s History Between the Tides and, more recently, Food Fights: How History Matters to Contemporary Food Debates.

Watch the talk

Why Do People Care for Sourdough? | Fermentology mini-seminars

Image attribution: © Tomas Castelazo,, CC BY-SA 4.0. Accessed from Wikimedia Commons.


Today I want to explore a set of questions that relate to the original Sourdough Project. That project included a survey that asked participants a handful of questions about the history of their sourdough — and that led to an unexpected avalanche of personal stories. In despair and faced with 152,000 words of personal stories, Erin McKenney, Lauren Nichols, and Rob Dunn hoped that a historian might help them make sense of all that abundance and the chaos involved.

The Sourdough Moment

As an historian I like to ask questions that seem obvious, but maybe aren't, and here's one: Why do people care so much about sourdough? They clearly do.

We're in some kind of sourdough moment right now. My news feed is full of stories. Some of them are about Instagram and about how you can make sourdough perfect and beautiful. Many people seem to be looking for something creative to do with all the extra time at home caused by the Covid pandemic.

Some people are starting their sourdough from scratch. They're creating starters, as they call them. But some sourdough starters, or cultures, as I prefer to call them, have been maintained for hundreds of years within families. And in some traditional societies and traditional communities, living fermentation cultures have been maintained for perhaps hundreds or even thousands of years. That's a long commitment by many generations of cooks, bakers, and brewers. For example, my family has maintained a sourdough starter for perhaps 120 years.

People clearly care about sourdough, but why do people care for sourdough? Why do they maintain these cultures over time? Why does my family? Why do I put the time in to maintain this particular ferment? What explains that long commitment to feeding and maintaining a living community in our homes?

Feeding sourdough that feeds us binds together and pairs human and microbial cultures in a multi-species community. This has intriguing implications for both the human story and for biological diversity.

My Family + Our Sourdough

I want to use one family's story to speculate about that commitment and about that relationship — and forgive me, it's my own family story.

Around the year 1900, one of my ancestors, Charles E. Bunnell, and his wife, Mary Ann Kline, graduated from Grinnell College in Iowa and moved directly to Kodiak Island, Alaska where they became schoolteachers. According to their daughter, Jean, the Bunnells received a gift of a bread starter from a sourdough — an Alaskan term for a prospector in the 1898 Klondike gold rush. Our family doesn't know if the prospector made that starter, that culture, locally or brought it from unknown origins outside Alaska as was often the case, and in fact, probably the case. Whatever its origins, that sourdough culture has been in my family ever since.

How it got to us though is quite a story, and I think may have much in common with other people's family sourdough stories. Either they weren't very good teachers, or perhaps they wanted a larger community in which to start a family, but Charles and Mary Ann soon moved to mainland Alaska. In 1914 Charles ran for Alaska territorial delegate to Congress and lost. He was appointed, however, as a territorial district judge in 1915 by newly elected Democrat Woodrow Wilson. Charles then served as Judge on the US District Court in Fairbanks for seven years.

Charles E. Bunnell, University of Alaska. 1921-1949. Alaska and Polar Regions Archives, Elmer E. Rasmuson Library, University of Alaska Fairbanks.

As soon as Republican Warren Harding took over, Charles was summarily fired. That's how federal judgeships worked back in the day — especially when they weren't for life. But he landed on his feet, and in fact, started a long family tradition of failing up. Charles Bunnell became the first president of the University of Alaska, and held that job for 28 years, from 1921 to 1949.

“Dr. Charles Bunnell and his moose calf. Calf died of eating too many pancakes.” (n/d). A. W. Bastress Collection, UAF-1972-142-17, Alaska and Polar Regions Archives, Elmer E. Rasmuson Library, University of Alaska Fairbanks.

Charles and Mary Ann raised their daughter, Jean, on the new campus of the University. The family ate bread, waffles, and pancakes made from their sourdough culture. So, unfortunately, did their family pet — a moose calf. A surviving photograph of Charles Bunnell from the Alaska State Archives is captioned: "Calf died from eating too many pancakes." So I think the lesson here is, feed your family your sourdough, but maybe not your pets.

Young Jean Bunnell grew up on the new campus of the University of Alaska. The University archives show Jean sitting with the campus Glee Club, out for a ride with her father in his fancy automobile, and posing, hands on hips, with her mother and her father. Jean left Alaska to go to college in California, and when she did she brought her sourdough culture with her.

Jean Bunnell in California, 1930s.

At Stanford, she became close friends with Catherine Morse, another northerner, from Bellingham, Washington. Catherine married her Stanford classmate Phil Kennedy and they had two daughters. When Catherine sickened with cancer she asked her closest friend, Jean, on her deathbed, to raise her daughters as her own. In 1958, when Catherine died, Jean Bunnell left her career at San Francisco State College and married Phil. Together they raised Sheila and Robin Morse Kennedy in San Rafael just north of the Golden Gate Bridge. And Jean brought her sourdough with her to her new family.

Jean and Phil eventually moved north to Eugene, Oregon, following Robin, who was for many years a teacher at the Waldorf School in Eugene. Of course, they brought their sourdough with them. Both Robin and Sheila raised their own families on sourdough pancakes, waffles, and bread. Both were extraordinary bakers and cooks. When I graduated from college and moved to Bellingham and later to Eugene, first Sheila and then Robin fed me on the sourdough family culture. Then eventually Robin gave me an earthenware crock and my own little piece of our family culture.

This sourdough culture is now dispersed throughout our extended family. It is fed by and feeding dozens of family members across North America. I think of this sourdough as a direct connection back to my ancestors who moved from Iowa to Alaska, from Alaska to California, from California back to the Northwest where I encountered this sourdough, which I then carried  to other parts of the Northwest, back to California, and eventually to Raleigh, North Carolina where I live now.

But I don't think of my connection to my ancestors via this sourdough as merely or only as family stories or shared recipes.

One of the things I've learned from the sourdough project is that this culture is a living thread that ties all of us together across the years. Like a pet that has outlasted all of us, the sourdough in my kitchen was once in Robin's kitchen, in Jean's kitchen, and in Mary Ann and Charles Bunnell's kitchen. It is a traveler through space and time, linking five generations of my family and counting.

The Stories We Share

For a long time, historians told the story of the past mostly as the story of those powerful enough to leave behind documents and sign treaties. Stories like my family's sourdough would not have made the cut. Historians wrote the past as the story of kings, but not peasants. Presidents, but not voters. Slaveholders, but not enslaved people.

Since the 1970s, however, my discipline of history has celebrated the diversity of human experience and acknowledged multiple perspectives. This includes the lives of women, of children, of people of color — and of the humble aspects of life, like what people ate, how they made a living, work, cooking, and baking. And it includes the living history of memory, of song, and of things never written down. Public historians are also interested in interpreting the contested memory of the past.

My family's sourdough culture, could it be part of that living history? Could something so humble really matter?

Microbial scientists, it turns out, have something to offer historians here. And I think the sort of punch line of this entire story will be that both historians and ecologists have something to offer one another. What the scientists are offering me in my thinking about the past is that they too have gone through their own reckoning in recent decades. The Sourdough Project is part of a rebirth of what people are now calling public science, in which scientists co-create science with the help of hundreds, or even thousands of participants. This allows much bigger, and I think much more interesting, questions like the ones that Erin and Lauren are asking.

In the Sourdough Project, hundreds of participants sent sourdough cultures to NC State. These created a library of living cultures that could be analyzed for the DNA within each of these cultures. The scientists ran analyses of these samples, these sourdough cultures, given by people all over the world. In so doing they created a kind of snapshot — not only of the community of organisms living in each of these samples, not just the yeast and the bacteria and how they might differ. But they also, perhaps inadvertently and perhaps intentionally, created a kind of living history of those communities as well. That is, they became very interested in how these communities formed and how they evolved over time. That is a history question as well. And one which I think implicitly carries with it stories.

So as I mentioned earlier, when Lauren and Erin sent out this survey asking participants to submit sourdough samples, they asked a series of questions as well, and here they are:

  • Would you be willing to send a sample of your sourdough starter?

  • Who made your sourdough starter, and what is their relation to you?

  • Does it have a name?

  • And then my favorite two questions: Why did you begin using sourdough, and why do you continue to tend it?

This project led to an avalanche of responses. Almost 1,000 people wrote back, and they contributed 152,103 words of stories about the sourdough that they sent in. These included responses to the questions asked, but also recipes, and all kinds of information that was never asked for at all. Stories about the meaning of the sourdough in each of these contributors' lives. Perhaps some of you reading this are some of those participants and you remember comments like this one: "One maintains this for its own sake. To sustain a living brew that my family will know holds me in it, was alive when I was struggling in school, and that has been alive alongside me for my life."

Studying Sourdough Stories

So how on Earth does an historian engage with 152,000 words of personal stories? Well, of course, we read, but that's a lot of reading. I borrowed some techniques from the digital humanities, and the first technique I borrowed is called text mining. I sorted this material and I removed the extraneous stuff like the word 'the' or numbers. What I ended up with was a body of words that I could search and visualize. The next step was to create a simple word cloud that allowed me to clean up all of this text and visualize the words that people used according to the frequency used.

Word cloud of text analysis.

Some of these words are unsurprising: wheat, rye, water, yeast, pizza, King Arthur (flour), beer. But the words that were most commonly used in people's responses to the Sourdough Project include: taste, began, find — and most of all, words about relationships and about time, like past, still, and friend. And of course the totally unsolicited word that appeared more than any other: love. How did love appear in this story of sourdough, and what do we do with that? That is a word that does not compute.

Photo in kitchen of sourdough.

This humble scene from my kitchen of the crock and the bowl, that's a scene that happened this morning in my kitchen. It's a scene that happens in millions of American kitchens every week and in hundreds of millions of kitchens worldwide.

These are fermentations: the food that we carry with us from the past, what Rob Dunn has called gardens of the past, and that we then pass on to those who come after us.

In each of those kitchens is a distinct microbial culture. This diversity–hundreds of millions of ferments worldwide–that diversity exists because of artificial selection by people. People favoring acid producing bacteria, which tastes good. Working with natural selection, by acid tolerant yeasts. These cultures are a vast living archive of biological diversity, and that archive is maintained by human beings. Our human cultures mingle with the microbial cultures, and we sustain one another. Without the people, you don't have these microbial cultures, this diversity. And without the microbial cultures, as we're coming to learn through studies of the microbiome in our guts and in our bodies, we too sicken and die.

Care + Sourdough

So why do people care for sourdough? I thought a lot more about this in the past year because my beloved Aunt Robin died last year. But not before she had children and grandchildren of her own. And not before she passed on her sourdough culture to many of us. Her sister Sheila also passed on that culture. Many of us now have some piece of Robin, not just her extraordinary laugh, the memories we have of her life, but also her own sourdough culture.

Robin Morris with grandchild.

Robin Bunnell Morse Kennedy Morris, 1951-2019.

Perhaps we care, all of us, for our sourdough cultures because we care for one another, and for the community that we are all part of. We have obligations, and we honor those in many small ways, including feeding those whom we love and passing along the cultures that fed us, as Robin did. Whether we know it or not, we are all part of multi-species communities that evolve over time, that incorporate us, and that carry on something of us even after we die.

I've speculated about a much larger process than the one that just applies to my family. But I think in the process of seeing how science and history come together and in asking the question, why do people care for sourdough?, we touch on some of the deeper questions that belong to all of us and to all of humanity.

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