Sourdough Bread
a San Francisco Tradition

From the time of the California gold rush in 1849, San Francisco has been renowned for its sourdough bread. For decades it appealed to the palates of gold miners, local residents and tourists alike. The bread, with its tangy flavor, is closely associated with the bay region. The unique flavor has variously been attributed to the city's fog, climate and local yeast. Some have even suggested that the flavor comes from San Francisco cable-car grease!

San Francisco has many icons and traditions: cable cars, the bridges, fisherman's wharf, the ferry building and many more. Sadly, the tradition of real gold-rush-era sourdough is largely dead.

Sourdough bread is traditionally made using a starter or sponge, a fermented dough-like mixture of flour and water containing a complex colony of microorganisms, including wild yeast and a special lactobacillus. The starter is mixed into the bread dough which is then allowed to proof. During proofing, the dough sits for several hours in a temperature-controlled environment of about 85 to 90 F.

Several bakeries in the bay area produced sourdough bread. The names are familiar to long-time residents of the area. Parisian was made in San Francisco; Toscana, Colombo and Baroni were made in Oakland. Pisano was made in Redwood City. The bread was distributed to regional grocers upon whose shelves could be found a half dozen or more different brands at any given time. In total, the bakeries turned out thousands of loaves and rolls every day.

The area's most popular sourdough was produced by the Larraburu Brothers bakery. Founded in 1896, the Larraburu bakery closed in May, 1976. The company had been involved in years-long litigation arising from an accident in which a Larraburu delivery truck struck and seriously injured a small child. In addition, one of the owners had taken on a great deal of debt in order to buy out his business partners. The large amount of debt contributed to the bakery's existing financial difficulties, resulting in its ultimate demise.

Beginning in the 1980s, bakeries dating back to the gold-rush era were acquired by corporate entities which introduced efficiency to the manufacturing process by cutting corners, changing recipes and shortening proofing times (the traditional manufacturing process typically requires about 16 hours). By the early 21st century these bakeries had closed and the legacy gold-rush-era brands had disappeared. One legacy brand survives. It caters mainly to tourists, but in this writer's opinion it is markedly inferior to the erstwhile brands of old.

So popular was San Francisco sourdough that in the late 1960s, Dr. Leo Kline and Frank Sugihara of the USDA Research Center in Albany, California, studied sourdough samples obtained from five local bakeries (Larraburu, Parisian, Colombo, Toscana and Baroni). They identified a naturally-occurring yeast known today as Candida humilis which leavens the bread.

The researchers also discovered a microorganism named Lactobacillus sanfranciscensis. It produces two acids which give San Francisco sourdough its unique flavor: lactic acid and acetic acid.

Contrary to popular myth, the lactobacillus and wild yeast are not endemic to San Francisco. The current thinking is that airborne yeast settles on wheat in the field and some is picked up in the milling process. The exact origin of the lactobacillus is uncertain, but it and the yeast have been found the world over.

Authentic San Francisco sourdough was made from just three ingredients: white wheat flour, water and salt. Note that no baker's yeast was used. The bread was leavened entirely by the naturally-occurring yeast in the sourdough starter. It wasn't until the USDA study that lactic acid and acetic acid were identified as the bread's souring agents; they account for the bread's tanginess.

Copyright Chris Clementson