Sourdough Symbiosis: Growing sustainability

Sourdough at Du Pain et Des Jeux bakery in Murat, France. Photo by DDP

In the quiet hum of kitchens around the world, a revolution is brewing. This revolution isn’t powered by advanced technologies or futuristic gadgets but by an ancient, humble process: the art of making sourdough bread. As sustainability becomes an increasingly urgent global issue, many are turning to traditional methods of food preparation to reduce their impact. Sourdough is symbiotic, building connections between the environment, communities, and generations. Sourdough has emerged as a symbol of this shift toward more sustainable living.

Sourdough and sustainability are interconnected, touching everything from environmental impact to local food systems, nutrition, and food waste reduction. To understand this connection, it’s important to explore not only how sourdough is made, but also how its process contrasts with industrialized bread production and how it fits into the broader context of sustainable food practices.

Sourdough bread begins with a simple combination of flour and water. Left to its own devices, this mixture attracts wild yeast and lactic acid bacteria from the environment and within its own bran. When first mixed, an initial population of microbes grows within sourdough starters. This then changes through a process called microbial succession. Eventually, certain species of lactic acid bacteria and yeast dominate the population

Over time, these microorganisms multiply, creating a starter — a living, breathing culture that can be nurtured indefinitely with some starters claiming to date back millennia. The starter is the heart of sourdough. It replaces the need for commercial yeast, which is a manufactured product created in industrial settings.

The wild fermentation process is central to sourdough’s sustainability. Unlike commercial yeast, which is cultivated in sterile environments and packaged for mass distribution, sourdough relies on naturally occurring microorganisms that are specific to the baker’s environment. This localizes the bread-making process and reduces the need for industrial intervention. Furthermore, the starter can be maintained and reused indefinitely, eliminating the need to continually purchase new leavening agents.

Homemade sourdough bread. Photo by Anton.

This contrasts sharply with the modern industrialized bread-making process, where commercial yeast is used to speed up production. While commercial yeast can make bread rise in under an hour, sourdough’s fermentation process is slow and deliberate, often taking anywhere from 12 to 48 hours. This longer fermentation not only enhances the flavor and texture of the bread but makes it easier to digest and increases its shelf life — both of which have important sustainability implications.

One of the most significant contributions sourdough makes to sustainability is its ability to reduce food waste. Globally, bread is one of the most commonly wasted food item with millions of loaves thrown away each year due to spoilage. Sourdough, however, has a natural advantage: its longer shelf life. The lactic acid bacteria produced during fermentation act as natural preservatives, slowing the staling process and preventing the growth of mold.

Sourdough bread stays fresher for longer than commercially produced bread, meaning fewer loaves are thrown away. Store sourdough cut side down, in a manner that slows dehydration (baggie, bread box, beeswax wrap). Even when sourdough does begin to harden, it’s often repurposed rather than discarded. Many bakers turn stale sourdough into croutons, breadcrumbs, or even use it to thicken soups or sauces.

Maintaining a sourdough starter encourages mindfulness. The starter must be regularly fed with flour and water, bakers often become more conscious of the ingredients they’re using and the waste they’re generating. Bakers often want to bring in artisan elements, choosing to use different types of flours, which can make the bread more costly. The more you invest, the less you’ll want to waste. Some bakers even find creative ways to use the discard from their starter. The discard is a percentage of the starter you remove when you re-feed it. The discard can be incorporated into pancakes, waffles, and other baked goods rather than throwing it away.

Sourdough baking often goes hand-in-hand with the use of local, organic, and heirloom grains. Many sourdough enthusiasts and artisanal bakers are committed to sourcing their flour from local farms that practice sustainable agriculture. This supports local economies and reduces the environmental footprint.

Sandwich with sourdough bread. Photo by Dan Burton.

Local grains often come from smaller-scale farms that use organic or regenerative farming practices. These farms prioritize soil health, biodiversity, and sustainable water use, which contribute to a healthier ecosystem. In contrast, the industrial agriculture system that supplies most commercial bread producers relies heavily on monocultures, synthetic fertilizers, and pesticides, degrading the environment over time.

Heritage grains — such as einkorn, spelt, and emmer — are particularly popular in the sourdough community. These grains have been largely replaced by modern wheat varieties in industrial bread production, but heritage grains offer sustainability benefits such as pest and disease resistance and deeper roots. Deep roots improve soil structure and help retain water, making them more drought-resistant.

By choosing locally grown and sustainably produced flour, sourdough bakers are making a conscious decision to support agricultural practices that prioritize the health of the planet. This shift toward more sustainable sourcing is part of a broader movement to rebuild local food systems and reduce the environmental footprint of our diets.

Another way sourdough contributes to sustainability is through its energy-efficient production process. While industrial bread production relies on large-scale machinery, temperature-controlled environments, and rapid fermentation, sourdough can be made with minimal equipment. In fact, many sourdough bakers still use traditional methods, such as hand-kneading and wood-fired ovens, which require less energy than industrial baking methods.

At the home-baking level, sourdough’s slow fermentation process doesn’t require constant supervision or energy-intensive techniques. The dough rises slowly at room temperature, and the long fermentation times often mean that baking can be done at off-peak hours, reducing energy use during times of high demand. Additionally, home bakers can plan their baking around their personal schedules, making sourdough adaptable and energy-conscious.

Sourdough has the potential to reduce energy consumption in the form of fewer trips to the store. Since sourdough bread lasts longer than commercially produced bread, bakers don’t need to purchase new loaves as frequently. They can choose the size of the loaf they want to make, opting for a large family size boule, or smaller loaves.

For those who maintain a starter at home, the ability to bake their own bread means they can opt out of the industrial food system altogether, reducing the carbon footprint associated with commercial bread production and distribution.

Sustainability isn’t just about the environment — it’s also about long-term health. Sourdough, with its long fermentation process, offers several nutritional advantages over commercially produced bread. The wild yeast and lactic acid bacteria in sourdough break down phytic acid, a compound found in grains that can inhibit the absorption of certain nutrients. This makes sourdough more nutrient-dense and easier to digest than bread made with commercial yeast. 

For people with gut issues, long-fermented bread can be significantly easier to digest, with spelt sourdough coming out as the winner for uneasy guts.

Sourdough has a lower glycemic index than many other types of bread, meaning it causes a slower rise in blood sugar levels. This makes it a healthier option for people looking to manage their blood sugar or reduce their risk of type 2 diabetes. A diet that supports long-term health is inherently more sustainable, as it reduces the burden on healthcare systems and promotes overall well-being.

The focus on whole grains and less-processed ingredients in sourdough baking aligns with broader efforts to promote sustainable eating patterns. Whole grains are not only more nutritious than refined grains, but they also require less processing, avoiding energy use and resource depletion in the food system.

Sustainability is more than reducing carbon footprints or conserving natural resources — it’s about fostering strong, resilient communities. Sourdough has long been a communal activity, from village bakeries in rural Europe to the modern resurgence of sourdough in urban kitchens. The process of making and sharing bread creates connections between people, fostering a sense of community that is essential for building a more sustainable society.

A strong sense of community makes sustainability easier. Photo by Helena Lopes.

In recent years, sourdough baking has experienced a renaissance, especially during times of crisis. When the COVID-19 pandemic disrupted global food supply chains and led to widespread shortages of commercial yeast, many people turned to sourdough as a way to bake their own bread at home. This resurgence in home baking highlighted the importance of self-sufficiency and local food production in times of uncertainty.

Sourdough is deeply connected to cultural heritage. For centuries, people have passed down sourdough starters through generations, preserving not only the microbial cultures but also the stories and traditions associated with them. In this way, sourdough serves as a living link to the past, a way of preserving culinary traditions that might otherwise be lost in the era of mass production.

By making sourdough, people are participating in a global tradition that spans cultures and continents, from the San Francisco sourdough pioneers of the Gold Rush to the traditional flatbreads of the Middle East. This cultural continuity is an essential part of sustainable food systems, as it ensures that knowledge and practices are passed down through generations, preserving the diversity of foodways that are so often threatened by industrialization.

While sourdough offers numerous sustainability benefits, it’s important to acknowledge the challenges that come with it. Sourdough baking can be time-consuming, requiring patience and dedication. For many people, particularly those with busy lives or limited access to local ingredients, maintaining a sourdough starter and baking bread from scratch is tedious and not worth the effort.

In some areas, access to locally grown, organic flour is limited, and the cost of these ingredients can be prohibitive. While sourdough can reduce food waste and reliance on industrial systems, the initial investment in time and resources may be a barrier for some people. The most successful acts of sustainability are the ones that are enjoyable and easy to sustain.

As sourdough has become more popular, it has also become commercialized. Many “sourdough” breads sold in supermarkets are made with shortcuts, using commercial yeast or additives to speed up the process. These products may not offer the same sustainability benefits as traditional sourdough and can mislead consumers into thinking they are making a more sustainable choice. 

Whether you ever make sourdough, the ties to sustainability are clear. Enjoy it how you like — a little avocado and a poached egg might do the trick.