round loaf of sourdough bread
What Makes San Francisco Sourdough Different?
The tangy flavor, aerated texture, and sour-sweet aroma in San Francisco-style sourdough comes from acetic acid — a byproduct of the fermentation process.
In the 1970s, scientists discovered a bacteria called Lactobacillus sanfranciscensis, which was believed to be indigenous and exclusive to the San Francisco Bay Area.
Although the bacteria has since been identified in other countries around the world, it's the same species that gives an extra bite to French and Italian country-style loaves.
Thanks to 'Frisco's long tradition of sourdough-making, starters that have been cultivated and passed down for generations are likely a contributing factor to the complex flavor.
It could also have something to do with the city's foggy climate. Josey Baker, co-owner of San Francisco's The Mill bakery, says it's actually more about the grains.
Baker told BBC, "The dominant force at work… is the grains from which each loaf of bread is made. Less of the acetic acid… and more of a sweet lactic acid-forward fermentation."