Fall is Primetime for Sourdough — the Mother of all Bread, Say its Advocates

Daily Hampshire Gazette, October 24, 2015 by James Heflin.

Jonathan Stevens, owner of Hungry Ghost Bread, and his employee Justin Knoll hoist a massive binful of dough onto a floured table at his Northampton bakery, and fold it over a few times. Flour dust billows outward, and the end result looks like it could crawl off the table and envelop a hapless passerby. Tomorrow, Stevens says, this giant mass will be cut into smaller portions that will become regular-sized loaves.

The folding is part of the long-form art of baking with sourdough, which Hungry Ghost uses for its many breads, a roster which includes French, annadama, spelt, rye and eight-grain. Though the term “sourdough” signifies a style of bread, to Stevens, “It’s not a style. That’s what bread is. That’s how real bread is made.”

Once you understand the difference between bread made with a sourdough starter and bread made with commercial yeast, it’s easy to see why Stevens and others hold such an unyielding opinion. Sourdough starter used to be the common way to make bread, before the advent of faster, more predictable commercial yeast in the late 19th century. In fact, some sources place its first use in ancient Egypt.

Though all yeast is alive, the bubbling slurry known as sourdough starter or “mother” is a more complex substance than a packet of baking yeast. When Stevens displays the starter at Hungry Ghost — “when kids come in,” he says, “we tell them this is the ghost” — the first thing that strikes you is the smell. It’s snap-your-head-back pungent, yeasty but with a sharp note of alcohol. It covers the bottom of a five-gallon bucket, and looks like batter.

Stevens says the starter makes “real bread” because of what’s producing the smell in that bucket. It’s a process driven by micro-organisms, one which changes bread’s qualities, making more of its nutrients accessible.
David Sela, a microbiologist and assistant professor in the University of Massachusetts department of food science, explains: “It involves a symbiotic relationship between bacteria and yeast.”

Jump-start on digestion

The bacteria and yeast come from the environment and the flour that’s mixed with water to make the starter; that flour-water mixture is a hospitable environment only to particular varieties, and they happen to be the varieties that make bread rise.

The yeast and bacteria digest the slurry of doughy water and produce alcohol and carbon dioxide, just as we produce gasses in our intestines when digesting something.

At Bread Euphoria in Leeds, baker and co-owner Mark Pollard says 95 percent of his bread is made with sourdough. One of the chief reasons is that digestive process. It turns out the starter is simply getting a head start on our internal digestion process.

Another baker who’s a fan of sourdough, David Henion of Henion Bakery in Amherst, explains further. “Our intestines are loaded with bacteria and single-celled creatures that do our digesting for us.” And of course, starter is a co-dependent colony of just such creatures. So, says Henion, “Sourdough helps pre-digest your flour for you.”

Pollard tells why that’s helpful. “In whole wheat there’s something called phytic acid. That blocks absorption of a lot of vitamins. If you eat a loaf of regular whole wheat bread, you’re not going to get all the vitamins they say are in there. Sourdough breaks down phytic acid, and gives you access to those vitamins.”

Feeding ‘mother’

So it makes sense, in a way, that Stevens’ massive pile of dough has a touch of sci-fi movie blob about it. It is alive, an external colony of creatures busy doing some of the otherwise internal work of digestion for us. The bread that results after other ingredients, like rye flour, spelt, or sweeteners are added to a portion of starter is simply dough that’s semi-digested.

If a sourdough starter is made from scratch, it takes at minimum a few days to be usable because of other organisms that may be initially present but die off in the inhospitable environment. But bakers usually keep a viable starter going indefinitely, continually feeding it with flour and water as they take chunks away to bake.
Sourdough cultures can last a very long time: Visit, and you can obtain, by merely sending an self-addressed stamped envelope, the micro-organisms from a starter that, it’s claimed, dates to 1847.

Stevens estimates his starter’s age as 12 years. To keep its external digestive process going, he and his employees have to take care of the starter, or mother, by feeding it twice a day. That’s a fairly simple process, involving pouring in water and flour and stirring. Stevens doesn’t always measure, instead he goes by consistency.

Each loaf requires a substantial amount of starter, so most of it gets used up fast. To make a batch of bread, some of the starter from the five-gallon bucket gets added to a mixture of flour and water. That mixture then starts its own fermentation process and after spending the night in the fridge, is on its way to bread-dom.

The starter that remains in the bucket gets fed and the organisms keep eating, producing carbon dioxide and alcohol. The bubbles of carbon dioxide – Henion calls them the “collective exhale” of the organisms — produce the dough’s rise and the holes in the finished loaf.

Alcohol may seem like a weird thing to have in dough, but it makes sense when you realize that the process unfolding in the starter is in part exactly what happens when you use yeast to create fermentation of grapes or grain to make alcoholic beverages. Only in breadmaking, the alcohol evaporates during baking.

In fact, says Henion, “Bread is just thick beer.”

There’s another major reason to like sourdough, of course. To most people, it simply tastes really good compared to bread baked with commercial yeast. “Baker’s yeast is like a one-note taste,” says Pollard. “Sourdough is kind of like a symphony. It’s got a lot of different flavors.”

Commercial yeast is consistent and fast, he says, but as with cheese and wine, time allows for the development of more complex tastes.

Stevens says that’s due to the presence of more lactic and acetic acids that develop over time. “It creates a more intense flavor,” he says.

San Franciso taste

A lot of people think of sourdough as a San Francisco thing, associating it with the pioneers of the Gold Rush era, for whom it was indeed a staple. But there’s a more specific association yet.

“There’s a link between San Francisco and a unique bacteria,” says Sela. Though he adds that the strain isn’t necessarily native to the city, it’s so associated with it that its scientific name is Lactobacillus sanfranciscensis. That strain and others like it come from the environment, even from bakers’ hands, and when they end up in a flour-water mixture, they thrive.

Pollard learned to bake in San Francisco, and he says that the reason the strain has become identified with the city has to do with its predominant temperature range of 65 to 75 degrees, apparently ideal for Lactobacillus sanfranciscensis.

Opinions of San Francisco starter vary among bakers.

Henion says he’s not a particularly big fan of San Francisco sourdough.

Pollard, on the other hand, says, “It’s an incredible starter.”

And here’s where things get complicated. Pollard continues: “When I first visited a bakery in the East, I said, ‘This doesn’t smell like the same starter.’”

And indeed, it isn’t — the starter he smelled was the product of local varieties of yeast and bacteria.

Which raises an interesting question. Can L. sanfranciscensis thrive in a starter in New England? Opinions vary here, too — Sela says that a strain brought here, if properly maintained, can remain the same. The bakers, on the other hand, all agreed that that strain would, over time, get overtaken by the local variety. If that is indeed the case, New England sourdough will always be one thing, San Francisco sourdough another.

Which is why Stevens says he sees the connection to San Francisco, no matter the flavor of the bread there, as unimportant.

The variation between strains of organisms in starter is not the only one that affects the end product. The mother changes with the seasons, says Pollard. “Bread tastes different in winter than in summer.”

That’s because higher or lower temperatures cause the mix of micro-organisms to change slightly. Yeasty flavors are more prominent in summer, bacterial ones in winter. “The yeast make fluffier bread, with a lighter flavor,” Pollard says. “The more pungent flavors come from the bacteria, so bread gets more sour and dense in the winter.”

But the prime season, he says, is fall. “In fall it’s like there’s a magic moment of baking where everything is great. The bread’s got really good volume, and a slight tang. That’s what I prefer.”

Henion’s taste is along the same lines. “Good sourdough doesn’t have a ton of that acidic flavor. A dough with tremendous sour flavor is one where, probably, a lot of the yeast has been consumed.”

The trick, all three bakers concur, is to keep the sourdough mother active. For Stevens, it’s a nearly mystical matter of its life force. He prefers, he says, a young and active starter, full of energetic organisms bent on multiplying, as opposed to “an old, wise strain,” one that’s been around a while and is less active. For the same reason, Pollard feeds his four times a day, compared to the common wisdom of twice per day.

More health potential

There’s another reason some people have become fans of sourdough. It’s part of why Stevens has become something of an evangelist about this time-honored, traditional manner of making bread.

Though none of the bakers or Sela are willing to claim the results are definitive, a recent, small-scale Italian study made an intriguing claim: Participants with celiac disease, which renders them intolerant of gluten, the part of wheat that enables it to stretch and rise rather than falling flat, were able to eat bread made with sourdough. That’s because, given sufficient fermentation time, the starter will digest gluten, too, bringing the bread’s gluten content down to safe levels.

Stevens believes it’s true, though he hastens to add, as all the bakers did, that if it is, no bread from his shop could be considered safe, given the clouds of flour dust that regularly fill the air there.

No matter the question of gluten intolerance, says Sela, sourdough is an important substance. He studies digestion of dietary fibers, and says fermentation processes like that of sourdough are a part of allowing the human digestive system to digest things it might not otherwise. Regarding the gluten question in particular, he says, “I think there’s merit to it.” He pauses. “But there’s also a case to be made for food being delicious. I think there’s a case that could be made for sourdough being a delicious product.”

Taming the beast

Back at Hungry Ghost, the sourdough process goes on. After Stevens has mixed new flour and water into his starter, he’s got a much different, fresher substance in the bottom of the bucket. He lifts his spatula, and globs of starter fall away. “You want a consistency like batter,” he says.

He walks over to tend some loaves at the end of the process, baking in the enormous oven. Then it’s back to get that massive blob, which he and Knoll have wrangled into a big plastic bin and then into its lair, a huge refrigerator, where it can rest overnight for tomorrow’s bake. The many styles of bread on the Hungry Ghost menu become blobs of their own. Four or five more bins are stacked in the corner, full of dough waiting to be folded.

No matter where it is, of course, given the right temperature, the starter will continue to ferment. A baker’s job is a permanent case of tending the process.

“We put dough in there to slow it down,” he explains. Because even bakers, he says, need to go home at the end of the day and get some sleep.

James Heflin can be reached at