Homebound during the Covid-19 outbreak, budding home bakers around the globe made sourdough baking their new hobby. Hailed as the “breakout star of pandemic-era kitchens” by The New York Times, sourdough became a national fascination as more people experimented with the microbe-enabled, tangy bread.

We asked three experts to share their thoughts on  the sourdough craze — educator Vanessa Kimbell (of The Sourdough School), bakery owner Azikiwee Anderson (Rize Up Bakery) and Karl De Smedt, curator of the world’s only sourdough starter library.

The question: How did the pandemic change the market for professionally-baked sourdough? Are more people making their own or are they buying from professional bakers?

Vanessa Kimbell, founder The Sourdough School

The pandemic changed the market in several ways. The first thing is, some of the large manufacturers that I’ve been talking to have been starting to appreciate and understand that people want real sourdough. And by that I mean sourdough that is genuinely long, slow fermented with wild yeast and lactic acid bacteria. They’ve also begun to appreciate the connection between bread and health. Authenticity and integrity are the two words that come to my mind when I think about how the pandemic has impacted the professional sourdough market. 

There’s no question that there was an exponential increase in home bakers making sourdough during the pandemic. It’s rather beautiful. I think when we were gifted the time to make those connections, so many of us used that. Will there be sudden change in behavior? People have now gone back to work and now I’d say there’s almost been a backlash against people wanting to take up sourdough. It became almost too trendy to the point where there can be a backlash. I have noticed there was a significant drop off as life has returned to normal. But that’s only to be expected. The joy of discovering we have a little freedom as a home baker making their own bread, I’d say it’s leveling back out again to pre-pandemic numbers.

 Azikiwee Anderson, founder Rize Up Bakery

I started baking like most of the world did during the pandemic. Normally we would all just go to the store and pick up whatever mediocre bread they had on hand, never thinking twice [that] it was full of preservatives and made with cheap industrial flour. Then all of sudden we had the thing that is always in short supply “TIME”! So we all tried to connect to the nostalgia of being self-sufficient since we had no real control over most things.

The sheer amount of people connecting to their food and what it is made of is what made it amazing for small new found bakers like me! The uptick in sourdough baking taught millions of people how hard it is and how good it could be. What more is there to say!

Karl De Smedt, curator The Sourdough Library, senior communication and training manager Puratos Center for Bread Flavour

Many consumers today are excited about sourdough bread. During the pandemic, many have started baking it at home and, on social media, sourdough reached a massive peak as a sign of consumer engagement. No wonder because it truly has a unique, rich taste. According to research by Puratos, 52% of today’s consumers know sourdough . Approximately 45% of consumers associate sourdough with “better taste” and nearly 30% associate sourdough with “Rustic,” “Healthier,” and “More Natural” – opening an excellent opportunity for value creation. 

For professionally-baked sourdough, there are immense opportunities. The most considerable evolution we see is that it will not matter who makes the bread in the future, but how it’s made — going from fast processes in two to three hours with only baker’s yeast. Or long processes with sourdough from 12 to 48 hours. A project like the Puratos sourdough library aims to discover more about the use of sourdough in all its aspects. We are sharing knowledge, preserving, and protecting the biodiversity of sourdough and bringing back the tradition used by more than 250 generations of bakers who used sourdough as their most precious ingredient in bread baking. That’s why, at Puratos, we believe the future of bread lies in its past. 

Microbes on our bodies outnumber our human cells. Can we improve our health using microbes?

“(Humans) are minuscule compared to the genetic content of our microbiomes,” says Maria Marco, PhD, professor of food science at the University of California, Davis (and a TFA Advisory Board Member). “We now have a much better handle that microbes are good for us.” 

Marco was a featured speaker at an Institute for the Advancement of Food and Nutrition Sciences (IAFNS) webinar, “What’s What?! Probiotics, Postbiotics, Prebiotics, Synbiotics and Fermented Foods.” Also speaking was Karen Scott, PhD, professor at University of Aberdeen, Scotland, and co-director of the university’s Centre for Bacteria in Health and Disease.

While probiotic-containing foods and supplements have been around for decades – or, in the case of fermented foods, tens of thousands of years – they have become more common recently . But “as the terms relevant to this space proliferate, so does confusion,” states IAFNS. 

Using definitions created by the International Scientific Association for Postbiotics and Prebiotics (ISAPP), Marco and Scott presented the attributes of fermented foods, probiotics, prebiotics, synbiotics and postbiotics.  

The majority of microbes in the human body are in the digestive tract, Marco notes: “We have frankly very few ways we can direct them towards what we need for sustaining our health and well being.” Humans can’t control age or genetics and have little impact over environmental factors. 

What we can control, though, are the kinds of foods, beverages and supplements we consume.

Fermented Foods

It’s estimated that one third of the human diet globally is made up of fermented foods. But this is a diverse category that shares one common element: “Fermented foods are made by microbes,” Marco adds. “You can’t have a fermented food without a microbe.”

This distinction separates true fermented foods from those that look fermented but don’t have microbes involved. Quick pickles or cucumbers soaked in a vinegar brine, for example, are not fermented. And there are fermented foods that originally contained live microbes,  but where those microbes are killed during production — in sourdough bread, shelf-stable pickles and veggies, sausage, soy sauce, vinegar, wine, most beers, coffee and chocolate. Fermented foods that contain live, viable microbes include yogurt, kefir, most cheeses, natto, tempeh, kimchi, dry fermented sausages, most kombuchas and some beers. 

“There’s confusion among scientists and the public about what is a fermented food,” Marco says.

Fermented foods provide health benefits by transforming food ingredients, synthesizing nutrients and providing live microbes.There is some evidence  they aid digestive health (kefir, sourdough), improve mood and behavior (wine, beer, coffee), reduce inflammatory bowel syndrome (sauerkraut, sourdough), aid weight loss and fight obesity (yogurt, kimchi), and enhance immunity (kimchi, yogurt), bone health (yogurt, kefir, natto) and the cardiovascular system (yogurt, cheese, coffee, wine, beer, vinegar). But there are only a few studies on humans  that have examined these topics. More studies of fermented foods are needed to document and prove these benefits.

Probiotics 

Probiotics, on the other hand, have clinical evidence documenting their health benefits. “We know probiotics improve human health,” Marco says. 

The concept of probiotics dates back to the early 20th century, but the word “probiotic” has now become a household term. Most scientific studies involving probiotics look at their benefit to the digestive tract, but new research is examining their impact on the respiratory system and in aiding vaginal health.

Probiotics are different from fermented foods because they are defined at the strain level and their genomic sequence is known, Marco adds. Probiotics should be alive at the time of consumption in order to provide a health benefit.

Postbiotics

Postbiotics are dead microorganisms. It is a relatively new term — also referred to as parabiotics, non-viable probiotics, heat-killed probiotics and tyndallized probiotics — and there’s emerging research around the health benefits of consuming these inanimate cells. 

“I think we’ll be seeing a lot more attention to this concept as we begin to understand how probiotics work and gut microbiomes work and the specific compounds needed to modulate our health,” according to Marco.

Prebiotics

Prebiotics are, according to ISAPP, “A substrate selectively utilized by host microorganisms conferring a health benefit on the host.”

“It basically means a food source for microorganisms that live in or on a source,” Scott says. “But any candidate for a prebiotic must confer a health benefit.”

Prebiotics are not processed in the small intestine. They reach the large intestine undigested, where they serve as nutrients for beneficial microorganisms in our gut microbiome.

Synbiotics

Synbiotics are mixtures of probiotics and prebiotics and stimulate a host’s resident bacteria. They are composed of live microorganisms and substrates that demonstrate a health benefit when combined.

Scott notes that, in human trials with probiotics, none of the currently recognized probiotic species (like lactobacilli and bifidobacteria) appear in fecal samples existing probiotics.

“There must be something missing in what we’re doing in this field,” she says. “We need new probiotics. I’m not saying existing probiotics don’t work or we shouldn’t use them. But I think that now that we have the potential to develop new probiotics, they might be even better than what we have now.”

She sees great potential in this new class of -biotics. 

Both Scott and Marco encouraged nutritionists to work with clients on first  improving their diets before adding supplements. The -biotics stimulate what’s in the gut, so a diverse diet is the best starting point.

Is fermentation the next big home kitchen technique? As more restaurants hire directors of fermentation, consumers are inspired to experiment at home.

An article in The Spoon makes a case for the rise of home fermentation equipment, which makes the process “a little less mysterious.”

“Fermenting is still viewed as something of a black art. Part of it is the weird and slightly creepy terminology (mother, anyone?). Mostly, though, it’s also because the act of farming bacteria to create tasty and healthy new foods is a far cry from the usual activity of assembling and cooking our meals in our kitchen.”

The article interviewed two entrepreneurs making their own fermentation devices: Breadwinner (which helps bakers know when their sourdough starter is ready) and Hakko Bako (a fermentation appliance). The creators say their products are making fermentation easy, controlled and approachable. Tommy Cheung of Hakko Bako notes food trends usually start in Michelin restaurants, then trickle down to casual dining and finally end up at the home kitchen. “I definitely think (home fermentation devices) are going to be a huge part of the future.”

Read more (The Spoon)

Analyzing the microbiome of a fermented food will help manage product quality and identify the microbes that make up the microscopic life. Though diagnostic techniques are still developing, they’re getting cheaper and faster.

“Why should we measure the microbial composition of fermented foods? If you can make a great batch of kimchi or make awesome sourdough bread, who cares what microbes are there,” says Ben Wolfe, PhD, associate professor at Tufts University. “But when things go bad, which they do sometimes when you’re making a fermented food, having that microbial knowledge is essential so you can figure out if a microbe is the cause.” 

Wolfe and Maria Marco, PhD, professor at University of California, Davis, presented on Measuring and Monitoring Fermented Food Microbiomes during a TFA webinar. Both are members of the TFA Advisory Board. During the joint presentation, the two gave an overview on microbiome analysis techniques, such as culture-dependent and culture-independent approaches.

Measuring Microbial Composition

Wolfe says there are three reasons to measure the microbial composition of fermented foods: baseline knowledge, quality control and labelling details.

“Just telling you what is in that microbial black box that’s in your fermented food that can maybe be really useful for thinking about how you could potentially manipulate that system in the future,” he says.

What can you measure in a fermented food? First there’s structure, which can determine the number of species, abundance of microbes and the different types. And second is function, which can suggest how the food will taste, gauge how quickly it will acidify and help identify known quality issues. 

Studying these microorganisms — unseen by the naked eye — is done most successfully through plating in petri dishes. This technique was developed in the late 1800s

“This allowed us to study microorganisms at a single cell level to grow them in the laboratory and to really begin to understand them in depth,” Marco says. “This culture-based method, it remains the gold standard in microbiology today.”

However, there’s been a “plating bias since the development of the petri dish,” she says. Science has focused on only a select few microbes, “giving us a very narrow view of microbial life.” Fewer than 1% of all microbes on earth are known. 

The microbes in fermented foods and pathogens have been studied extensively.“Over these 150 years we have now a much better understanding of the processes needed to make fermented foods, not just which microbes are these but what is their metabolism and how does that metabolism change the food to give the specific sensory safety health properties of the final product,” she says

Marco and Wolfe both shared applications of these testing techniques from research at their respective universities.

Application: Olives

At UC Davis, Marco and her colleagues studied fermented olives. Using culture-based methods, they found that the microbial populations in the olives change over time. When the fruits are first submerged for fermentation, there’s a low number of lactic acid bacteria on them — but within 15 days, these microbes bloom to 10-100 million cells per gram.

Marco was called back to the same olive plant in 2008 because of a massive spoilage event. The olives smelled and tasted the same, but had lost their firmness.

Using a culture-independent method to further study what microbes were on the defective olives, she discovered a different microbiota than on normal ones, with more bacteria and yeast. 

The culprit was a yeast.“Fermented food spoilage caused by yeast is difficult to prevent,” Marco says. “New approaches are needed.”

Application: Sourdough

At Tufts, Wolfe was one of the leaders on a team of scientists from four different universities that studied 500 sourdough starters with an aim to determine microbial diversity. Starters from four continents were examined in the first sourdough study encompassing a large geographic region.

The research team identified a large diversity among the starters, attributed to acetic acid bacteria. They also found geography doesn’t influence sourdough flavor.

“Everyone talks about how San Francisco sourdough is the best, which it is really great, but in our study we found no evidence that that’s driven by some special community of microbes in San Francisco,” Wolfe said. “You can find the exact same sourdough biodiversity based on our microbiome sequencing in San Francisco that you can find here in Boston or you could find in France or in any part of the world, really.” 

Wolfe and Marco will return for another TFA webinar on July 14, Managing Microbiomes to Control Quality

Sourdough was the “breakout star of pandemic-era kitchens,” so it’s no surprise that sourdough hobbyists are turning their newly-found craft into a profession. There’s a new wave of bakers obtaining Cottage Food Operations licenses so they can sell their homemade bread. Max Kumangai (pictured), an unemployed Broadway actor, was one of many who started a bread-baking business during the pandemic.

“It’s a really exciting time,” says  Mitch Stamm, executive director of the Bread Bakers Guild of America. “Many small bakeries — one-person bakeries, two-person bakeries — they are doing beautifully.” The Guild says recessions have historically fueled passion in cooking and baking. Home bakers are finding their new quarantine hobby is a passionate career move, allowing them to create delicious food and socialize with customers.

“For sure there was a feeling, ‘I hate my job, I hate my life, I’m going to wake up and follow my heart,’” says Penny Stankiewicz, a pastry and baking arts instructor at the Institute of Culinary Education. That school  received 85% more applications in 2020 compared to 2019.

Read more (The New York Times)

Behind every fermented food or beverage is  intriguing science that creates a pleasantly tangy taste. Customers want to know all about that chemical process, right? 

No. Stop geeking out and appeal to the foodie instead.

“This is about the joy of eating, and so when you over-science me and you over-gut me, I forget the joy of eating. Remind yourself that your most important message is how pleasant, how tasty, how engaging, that’s the pleasure of eating, and then you can tell me how you make that pleasure,” says Sasha Strauss, managing director at Innovation Protocol (a marketing consulting & design agency). Strauss shared his brand strategy tips in the TFA webinar Building a Fermented Brand. He stressed fermented brands need to avoid getting stuck in the “scientific nuance of how you make your products. I’m not saying delete the science, just don’t make it the marquee.”

Alex Corsini, founder of frozen pizza company Alex’s Awesome Sourdough (and TFA Advisory Board member) agrees. Corsini, who moderated the webinar, says he began his brand with a heavy emphasis on the science of fermenting sourdough.

“Our customer didn’t really respond to that. And that’s something I see in fermentation all too often, is people aren’t selling the actual benefit. They want to understand the benefit, so that’s what you lead with,” Corsini advises. 

If you’re selling kombucha, for example, share that it’s a feel-good product that will make you feel better than a soda, Corsini says. Don’t make your selling pitch the SCOBY’s technical specifications.

Teach, Don’t Sell

“I don’t understand fermentation. I don’t understand the health benefits. I don’t understand its cultural origins. I don’t understand what section to buy it in. I don’t understand what to eat it with or who to serve it too. Your first duty as a brand is to help me make sense of this, help me understand it,” Strauss says. “It’s not your job to be the sexiest, raciest, the most innovative, it’s your job to help me understand. And where understanding sits in the consumer’s mind is where buying behaviors originate. So the first and most important duty of your brand is to simply help me not feel alone, help me not feel confused, help me not feel overwhelmed.”

By educating the consumer, by inspiring them to learn about fermentation, “they will be indelibly connected to you,” Strauss continues. “They will prefer you. They won’t wonder if your price is a penny cheaper, they’ll prefer you because you’re who they learned from. We buy who we learn from.” 

There’s not enough room on a label to detail all the health benefits or the scientific details of a product. But this information can go on a brand’s website, social media page or table-top display at a trade show or farmer’s market.

“I hope that your audience doesn’t hear from you just once,” Strauss says. They should find a video of your product on Instagram, find recipes on your website and see an ad in the local paper. Brands need to create multiple opportunities to engage, “don’t try to cram all of your value in a single channel.” 

A New Economy

The COVID-19 pandemic has permanently changed the economy. Consumer lifestyles have changed, too, and these new  behaviors create opportunities, especially for fermented products that are healthy and flavorful.

“Historically, if you were trying to build a consumer packaged goods brand, it was really about your resume, your long list of accomplishments , your heritage in farming, your understanding of the chemistry and that was what marked the person, the business, the brand,” Strauss says. “But actually now, it’s really about how you resonate, how I connect with you, how you inspire me, and that doesn’t require a long history, that requires a contemporary participation.”

“In a world where the audience is starting and ending their search digitally, each of the things that you share, post, write about, blog about, video dialogue about, those things are little breadcrumbs that will never go away,” Sasha says. “They’re little trails that lead to your brand, lead to your resources, lead to your understanding and this is powerful.”

Consumers rejected traditional brand loyalties this past year. They’re increasingly open to new brands, curious about new cultural flavors and want healthy food. Critically, Strauss points out, they want to purchase from socially responsible brands. “In a post-covid era, we want a brant to also do good,” he says.

Producers must make conscious choices about the farmers they use — how are they improving soil health? What is the environmental impact of their distribution line?

“Understand you have to make an impact, somehow do good for the world while building business,” Strauss says.

Trends in Pandemic Eating

Consumers increasingly embraced adventurous and healthy food over the last twelve months, but “a big pandemic winner is fermented foods.” 

An article from the Associated Press details how, now a year into isolation, people are cooking beyond comfort food. They’re “embracing foods long forgotten or rejected for taste, texture or smell.” Anne Alderete (pictured) details how she is finally enjoying natto (fermented soy beans) after rejecting it for years. 

Read more (Associated Press)

The World of Fermented Foods

In the latest issue of Popular Science, a creative infographic illustrates “the wonderful world of fermented foods on one delicious chart.”  It represents “a sampling of the treats our species brines, brews, cures, and cultures around the world,” and is particularly interesting as it shows mainstream media catching on to fermentation’s renaissance. Fermentation fit with the issue’s theme of transformation in the wake of the pandemic.

Read more (Popular Science)

Results of the first large-scale study of sourdough starters were released last week — and the conclusions are fascinating, challenging myths about sourdough. Scientists from four different universities studied 500 sourdough starters from four continents, with an aim to determine microbial diversity. 

“We didn’t just look at which microbes were growing in each starter,” says Erin McKenney, co-author of the paper and an assistant professor of applied ecology at North Carolina State University. “We looked at what those microbes are doing, and how those microbes coexist with each other.”

The most striking finding: geography doesn’t matter.

Sourdough enthusiasts preach that location and climate will alter  sourdough flavor. San Francisco has long held bragging rights for the most distinctive taste profile. But, of the 500 samples, there was little evidence of geographic patterns.

“This is the first map of what the microbial diversity of sourdoughs looks like at this scale, spanning multiple continents,” says Elizabeth Landis, co-lead author of the study and a PhD student at Tufts. “And we found that where the baker lives was not an important factor in the microbiology of sourdough starters.”

Alex Corsini, CEO and founder of sourdough pizza brand Alex’s Awesome Sourdough (and TFA advisory board member), says the research “demystifies the misconception that sourdough is only good in certain pockets of the world such as San Francisco.” Great sourdough, he says, is about the raw materials.

“It further shows why sourdough is ubiquitous all over the world — starters can thrive anywhere as nature provides the magic and bakers just need to be in a position to coax out a result without ruining the magic — the magic here being the microbial balance needed to ferment and levain baked goods,” Corsini says.

The research also found there is no one single variable responsible for sourdough variations, bucking conventional baking wisdom. 

“What we found instead was that lots of variables had small effects that, when added together, could make a big difference,” says Angela Oliverio, co-lead author of the study and a former PhD student at the University of Colorado, Boulder. “We’re talking about things like how old the sourdough starter is, how often it’s fed, where people store it in their homes, and so on.”

As a commercial sourdough producer, Corsini values the “low and slow” process to master a sourdough batch, especially when making it consistently on a large scale. Alex’s Awesome Sourdough undergoes a 70-hour ferment using high-quality flour, filtered water and a decades-old starter. 

“Although location makes little or no impact on the starters microbial ecosystem, regulating temperature and time is fundamental and adjustments need to be made based on the location you are in (hot climate, cold climate, humidity, etc.) to get a desired result,” Corsini says. “We make slight adjustments throughout the year to ensure a consistent texture and flavor in our dough.”

The study found variations in dough rise rates and aromas were due to acetic acid bacteria, “a mostly overlooked group of sourdough microbes.” The bacteria slowed the rise time and gave the sourdough a vinegary smell. Researchers were “surprised” that 29.4% of the samples contained acetic acid bacteria.

“The sourdough research literature has focused almost exclusively on yeast and lactic acid bacteria,” says Ben Wolfe, co-author of the study, associate professor of biology at Tufts University (and also a TFA advisory board member). “Even the most recent research in the field hadn’t mentioned acetic acid bacteria at all. We thought they might be there to some extent, since bakers often talk about acetic acid, but we were not expecting anything like the numbers we found.”

The 500 sourdough starters studied mostly came from home bakers in the U.S. and Europe. Researchers performed DNA sequencing for each sample, narrowing down to 40 starters as being representative of the diversity of the original array. 

Those 40 were: assessed by sensory professionals for aroma profile, chemically analyzed to determine the organic compounds released by each and then measured for dough rise time.

“I think it’s also important to stress that this study is observational — so it can allow us to identify relationships, but doesn’t necessarily prove that specific microbes are responsible for creating specific characteristics,” says Wolfe. “A lot of follow-up work needs to be done to figure out, experimentally, the role that each of these microbial species and environmental variables plays in shaping sourdough characteristics.”

“And while bakers will find this interesting, we think the work is also of interest to microbiologists,” Landis adds. “Sourdough is an excellent model system for studying the interactions between microbes that shape the overall structure of the microbiome. By studying interactions between microbes in the sourdough microbiome that lead to cooperation and competition, we can better understand the interactions that occur between microbes more generally — and in more complex ecosystems.”

The research, “The Diversity and Function of Sourdough Starter Microbiomes,” was done with support from a National Science Foundation grant. 

The Science Behind Sourdough

Sourdough has become the darling of the pandemic pantry, as people experiment with a starter of microbes in their home kitchen. Scientists are just beginning to “discover that the microbes in a sourdough depend not just on the native microbial flora of the baker’s house and hands, but also on other factors like the choice of flour, the temperature of the kitchen, and when and how often the starter is fed,” according to an article in Scientific American. The magazine interviewed multiple microbiologists on the science behind a great sourdough loaf.

“When we study sourdough science, we learn that we know remarkably little for a technology that’s — what? — 12,000 years old,” says Anne Madden, a microbiologist at North Carolina State University.

Read more (Scientific American)