Before prepackaged yeast was invented, French loaf bread was made with wild yeast, found in the air.
Wild yeast differed depending on where you were, and so the taste of a loaf of bread depended on the place from which bakers ‘captured’ their wild yeast.
When French bakers came to San Francisco during the Gold Rush, they used this ‘wild yeast’ technique… and got slightly different results.
Upon tasting the bread, they noticed that their loaves were a bit more sour than usual.
Basically, sourdough bread in SF was discovered by mistake…
…but a delicious one, at that. And it’s not necessarily where sourdough was invented; it’s believed that this technique has been employed throughout centuries.
Bakers believed that the weather was the culprit for the bread’s distinct taste.
They continued to capture wild yeast from the humid air of San Francisco and let this yeast reproduce. The dough in which the wild yeast is continually reproducing is called ‘mother dough’ or ‘starter’ dough.
The strain of bacteria that puts the ‘sour’ in sourdough was aptly named lactobacillus sanfranciscensis, after its place of discovery.
Not that sourdough bread is only made in San Francisco. Others have since discovered that making sourdough bread using the wild yeast technique is possible, as long as you capture this lactobacillus.
Fun fact: It turns out this bacteria also keeps sourdough bread from molding.
Not only do the interactions between the lactobacillus and the yeast yield delicious-tasting bread, but there’s also an antifungal quality to the bacteria when paired with the dough.
The cultivation of this sourdough bread-baking technique in SF has created a ‘bread culture’ (pun intended) that you can’t find anywhere else.
With the discovery of sourdough bread, a whole new subset of bakers emerged; all of whose goods were equally scrumptious.
Boudin is credited as the founding bakery of SF sourdough bread.
It’s the oldest and longest-running sourdough bread business in San Francisco. Today, Boudin Bakery is located on Fisherman’s Wharf, where it even has a museum and runs tours of the bakery.
And there are plenty of other bakeries whose passion is sourdough.
In sum, if you need a sourdough bread fix, San Francisco is your city.