How to make and keep a sourdough bread starter

You'll never need to buy yeast again

For several thousand years, all bread was technically sourdough, says Baking and Pastry Arts chair Alan Dumonceaux (Baking ’05). Nobody knew a thing about yeast. It just happened that, under certain conditions, dough would rise to be baked into bread, may the gods be praised.

In fact, it wasn’t until 1815 that French chemist Joseph-Louis Gay-Lussac linked fermentation with the single-celled fungi. Then, in 1859, Louis Pasteur, of pasteurization fame, described the reaction, ultimately leading to ready-to-use Saccharomyces cerevisiae, commonly sold as baker’s yeast.

Research removed uncertainty from breadmaking, and enabled industrial scale-up. It also made life much easier for the home baker – even if it was unnecessary. Yeast, after all, is free.

“We live in an environment of wild yeast,” says Dumonceaux. “It’s all around us, all over us, at all times.” Thankfully, we don’t see that, which may be why sourdough breadmaking continues to have an air of mystery about it.

Dumonceaux would rather it didn’t. “Ideally, you shouldn’t eat any bread that hasn’t been fermented properly,” he says, for the right amount of time and by the right organisms. Fermentation modifies gluten to make it more digestible. What’s more, “The goal of making any type of yeasted breads is to have a terrific flavour, and flavour comes from fermentation.”

We asked Dumonceaux, a veteran of Paris’s World Cup of Baking, about making bread the way our ancestors did, about abandoning off-the-shelf microbes, and if becoming the steward of a sourdough starter, or levain, means you can never go on vacation again.

How to make a starter

sourdough starterDumonceaux uses whole-grain rye flour for the first feeding because it contains more natural sugars, kickstarting fermentation. (He’s written about this process extensively, by the way, in an industry journal.) He mixes 100 grams of flour with 100g of water in a covered container at 21 C. It sits for 24 hours.

At first, little happens. Fermentation begins after the next step: Dumonceaux keeps 40g of the mix and adds 100g each of untreated flour (not rye) and water and waits another 24 hours. On the third day, he repeats the process, but increases the frequency to twice a day.

Make your own sourdough

You’ve got your starter. It’s bubbling! Now what? Make sourdough bread, of course!

Among the easiest ways is the no-knead method. Here’s a recipe and method, courtesy of NAIT Baking and Pastry Arts chair Alan Dumonceaux.

There’s a Darwinian process at work here. Sourdough microbes produce acid, which alters the environment so that it supports only those organisms that are up to the task of fermenting dough. At first, it isn’t pretty.

There’s a Darwinian process at work here. At first, it isn’t pretty.

“The culture will have a very unpleasant aroma,” Dumonceaux wrote in Bakers Journal in 2017. “But as the level of activity increases and the culture is on its intended journey to become a starter, the aroma will begin to improve.”

By day 10, after a consistent feeding schedule at room temperature, you should be be able to begin using starter for breadmaking. The signal is that it grows in size three times within half a day of feeding (keep it in a clear container so it’s easy to tell).

At that point, you’ll also be able to relax, Dumonceaux adds. Starters are tougher than you might think.

How to maintain your starter

Keeping a sourdough starter doesn’t mean you’ve added another mouth to feed. Getting it established takes about two weeks of care, says Dumonceaux. After that, “You can abuse it.”

He’s guilty of this himself. Before Dumonceaux went to Paris to test himself against the world’s best bakers in 2016, he put his starter in the fridge. It wasn’t until seven months later that he took it out again, let it warm and stirred in the layer of what’s known in the industry as “hooch” – the clear, boozy liquid that forms naturally at the top of the mix. Then he began feeding on a 24-hour schedule.

By day four, Dumonceaux was making bread again.

Really, losing a starter isn’t a big deal.

Really, losing a starter isn’t a big deal – even if it’s the one supposedly passed down from your great-grandmother. “That's just pure romanticism,” says Dumonceaux. After about a year, he points out, the microbial makeup of a starter will reflect the environment it’s in, not the one it came from.

What to do with excess starter

sourdough breadDumonceaux is mindful of the ethics of discarding starter during the feeding process, and that some will consider it wasted food. He has a solution: “You can use sourdough beyond bread.”

“You can use sourdough beyond bread.”

He puts it in everything, from pancakes to tea biscuits to croissants to Danishes, adjusting recipe hydration levels as necessary. And demand is high. Since starting to make bread for the office at NAIT, Dumonceaux says that staff won’t eat anything else. That’s a good thing – he has very active and healthy starter, and he’s always happy to find ways to put it to work.

“There are many different places that you can use sourdough,” he says. “It only makes your product better.”

Troubleshooting your starter

For overactive starter: Drop the temperature of the water you use to feed your starter. Dumonceaux prefers eight to 10 C. This slows its progress toward the “high-water line,” that three-fold expansion at which you can make bread.

For underactive starter: Try the opposite – use warmer water if your house is cool (which also means cooler flour). Twenty-five to 30 C should do.

For thin starter: Your starter shouldn’t be thick as dough but it shouldn’t be a runny slurry either. For a happy medium, Dumonceaux recommends holding back water and adding a pinch of salt to “tighten up proteins.” Note how much you added, though, and dial back the salt in the final recipe accordingly.

Subscribe to receive more great stories every month

Find out more news about NAIT, stories about our alumni and their impact on their communities, and useful how-to content featuring our experts.

Sign up today »