Why sourdough went viral

By Josie Delap

Shortly before the world shut down in response to covid-19 someone tweeted that a “sourdough starter is a Tamagotchi for people in their 30s”. The analogy, no doubt irritating to diligent bakers, is apt. Like the diminutive digital pets, you have to regularly feed your sourdough starter – the gloop of wild yeast and accompanying bacteria used to leaven this type of bread. You can overfeed both. Though you can leave your starter to slumber in the fridge for a while, ignore it for too long and, like a Tamagotchi, it will perish. In the (currently unimaginable) event that you jet off on a long holiday, it is now possible to check your starter into a sourdough hotel, which will lavish care on it until you return.

No one country can lay claim to sourdough, but the Egyptians may have been the first to bake bread raised with wild yeast. In 2019 Seamus Blackney, a scientist who became a video-game designer, baked a loaf using a starter based on a 4,500-year-old yeast from Egypt. From the Middle East it spread north, through Europe and beyond. Each sourdough starter varies just slightly from one to the next, depending on the micro-organisms in the air, flour and water where it was made, and those on the hands of the mixer. Blackney used yeast from the Puratos Sourdough Library in Belgium – mission statement: “to preserve the biodiversity of leaven agents” – which has more than 90 starters in its vaults, from 25 countries. Most are from Europe. In the northern reaches of the continent sourdough is often made with 100% rye flour. Elsewhere lighter sourdoughs are more common. Some are protected by European regulations, such as Italy’s pane di Altamura, which is made with semolina flour, and Spain’s pan de Cea. These must be leavened with wild yeast.

Today San Francisco makes the most strenuous case to be the sourdough capital of the world. During the California Gold Rush in the mid-19th century, miners brought starters with them, clasping them close at night to ensure that the yeast didn’t perish in the cold. In the 1960s Tassajara, America’s first Zen Buddhist monastery, was founded in California. Edward Espe Brown, one of the monks, published the “Tassajara Bread Book” in 1970; it is now in its 25th edition and remains beloved by many American bakers.

Over time however, tamer, modern, mass-produced yeast has come to dominate our bread baskets. Julia Child, one of the giants of the American kitchen from the 1970s to the 1990s, dismissed America as a country where the bread “tastes like Kleenex”. How could such a land be great, she wondered. She would surely have delighted at the recent resurgence of sourdough, which, like a well-fed starter, has taken on a life of its own.

The pandemic popularity was practical at first. Artisanal bakers were closed. Supermarket sourdough may well be laced with commercial yeast. Starved of bread, and with more time on their hands, many people decided to bake their own. That led to the great yeast shortage of 2020. Sourdough was the answer (assuming you could get your hands on the flour). Where pictures of restaurant meals or shots of holiday beaches once flourished on Instagram, photos of bread soon took over.

The pleasures of sourdough are more profound than a picture-perfect crumb. The dough is stretched and folded and spun and folded again and again and again. Disappointingly, it does not require much kneading: there is none of the catharsis provided by the rhythmic slapping and pummelling of other kinds of dough.

But be warned: baking sourdough is a risky business. At a time when profound uncertainty already underpins every aspect of life, sourdough ushers in another kind of unpredictability. Everyday bakers’ yeast contains a single microbe, saccharomyces cerevisiae: it is reliable, fast and easily available (at least outside the unusual constraints of a pandemic), and produces loaf after identical loaf.

A sourdough starter, by contrast, is made from nothing more than flour and water, fermented into bubbly, yeasty magic, and contains multitudes of microbes. So the outcome is erratic. How lively will it be? Will the loaf rise at all? How long do you hold your nerve before removing it from the oven? Will the crust be a caramelised delight or a pallid disappointment? What kind of air bubbles will appear when at last you slice it?

Unlike life’s general unease, however, the unpredictability of sourdough is thrilling. The starter and the dough are affected by a flurry of factors: humidity, temperature, how many times you chose (or remembered) to manipulate the dough. Even if you feed your starter with flour from the same bag, with water from the same tap, bake with the same ingredients in the same dish in the same kitchen, no loaf will turn out the same. At a time when day follows day, when the monotony of our newly narrowed horizons threatens to overwhelm us, the surprising rise of your daily bread can start to feel like a blessing.■

ILLUSTRATION JAKE READ

Image: Stockfood